Android: add Android Studio support, completely redone java part (#9066)

.gitignore

@@ -3,6 +3,7 @@
 *.swp
 *.bak*
 *.orig
+.DS_Store
 # Vim
 *.vim
 # Kate
@@ -77,17 +78,11 @@ doc/mkdocs/mkdocs.yml
 ## Build files
 CMakeFiles
 Makefile
-!build/android/Makefile
-build/android/path.cfg
-build/android/*.apk
-build/android/.externalNativeBuild
 cmake_install.cmake
 CMakeCache.txt
 CPackConfig.cmake
 CPackSourceConfig.cmake
 src/test_config.h
-src/android_version.h
-src/android_version_githash.h
 src/cmake_config.h
 src/cmake_config_githash.h
 src/unittest/test_world/world.mt
@@ -109,16 +104,3 @@ cmake_config.h
 cmake_config_githash.h
 CMakeDoxy*
 compile_commands.json
-
-## Android build files
-build/android/src/main/assets
-build/android/build
-build/android/deps
-build/android/libs
-build/android/jni/lib
-build/android/jni/src
-build/android/src/main/jniLibs
-build/android/obj
-build/android/local.properties
-build/android/.gradle
-timestamp