Migrate left/right to start/end #supportsRtl

[mmathieum]

• [x] Requires: minSDK Android 4.2 (API level 17) -> Can remove left/right entirely
• [x] XML: paddingLeft -> paddingStart
• [x] XML: paddingRight -> paddingEnd
• [x] XML: layout_marginLeft - > layout_marginStart
• [x] XML: layout_marginRight-> layout_marginEnd
• [x] XML layout_alignParentLeft -> layout_alignParentStart
• [x] XML layout_alignParentRight -> layout_alignParentEnd
• [x] XML android:left + android:start (minSDK 23)
• [x] XML android:right + android:end (minSDK 23)
• [x] XML layout_toLeftOf -> layout_toStartOf
• [x] XML layout_toRightOf -> layout_toEndOf
• [x] XML: "left" -> "start"
• [x] XML: "right" -> "end
• [x] Java/Kotlin: getPaddingLeft() -> getPaddingStart()
• [x] Java/Kotlin: getPaddingRight() -> getPaddingEnd()

https://developer.android.com/training/basics/supporting-devices/languages#SupportLayoutMirroring

[mmathieum]

https://github.com/mtransitapps/commons/commit/e27a6677806d8f6e5fde58b146bd31ecbcf8c59f

https://github.com/mtransitapps/commons-android/commit/6fbffabc3a42a5b7d9c67ac5d5c8344713718142

https://github.com/mtransitapps/mtransit-for-android/commit/3b37290c9221fe3a6ad98c3bf5ab02152c3b4d32

https://github.com/mtransitapps/mtransit-for-android-gradle/commit/82c12b0336b3528c784e5423edde7defd530b6d0

[mmathieum]

https://github.com/mtransitapps/mtransit-for-android/commit/620be709d5b44409219f23d58ada11465e07aec0

https://github.com/mtransitapps/mtransit-for-android-gradle/commit/b5dc2a6d78aeace6b43931d31d4098af2a52e889