The purpose of this PR is to fix the bellow error:
Stack Trace
```
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':react-native-picker_picker:packageDebugResources'.
> Error: 6 exceptions were raised by workers:
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation.
File was preprocessed as vector drawable support was added in Android 5.0 (API level 21)
See http://developer.android.com/tools/help/vector-asset-studio.html for details.
```
The purpose of this PR is to fix the bellow error:
Stack Trace
``` FAILURE: Build failed with an exception. * What went wrong: Execution failed for task ':react-native-picker_picker:packageDebugResources'. > Error: 6 exceptions were raised by workers: java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. java.lang.RuntimeException: java.lang.RuntimeException: Error while processing /Users/reberthkelvin/Projects/Delfos/delfos_im/DelfosimApp/node_modules/@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml : Can't process attribute android:fillColor="@android:color/black": references to other resources are not supported by build-time PNG generation. File was preprocessed as vector drawable support was added in Android 5.0 (API level 21) See http://developer.android.com/tools/help/vector-asset-studio.html for details. ```Ref: https://stackoverflow.com/questions/51325513/cant-process-attribute-androidfillcolor-androidcolor-white/53846109#53846109