Update code for buiding with the code and build environment of API 30 (Android 11)

[g7fernandes]

Several updates to make the code work again, following the instructions and requirements for Android API 30.

• [x] Create script to copy the files of this project into the adequate directories in the AOSP directory tree;
• [x] Migrate build commands from make files to android blueprint files;
• [x] Update manifests for compatibility with API 30;
• [x] Create fragment of the vendor compatibility matrix;
• [x] Fix java compilation error for the helloworldservice
• [x] Review the app helloworld (that consumes helloworldservice);
• [x] Check for the necessity of init file (so the service can start automatically) (not needed);
• [x] Reorganize de directories to resemble the location of the source and configuration files in the AOSP directory tree;
• [x] Update and expand readme. Put references to AOSP documentation better explaining the necessity of the SDK and how to build this project.

[oliveirarleo]

+1 for testing!