Merge "[2nd] Add cluster count API" into main

core/api/current.txt

core/java/android/text/BoringLayout.java

core/java/android/text/Layout.java

core/java/android/text/TextLine.java

core/tests/coretests/src/android/graphics/PaintTest.java

core/tests/coretests/src/android/text/TextLineTest.java

graphics/java/android/graphics/Paint.java

libs/hwui/hwui/MinikinUtils.cpp

libs/hwui/hwui/MinikinUtils.h

libs/hwui/jni/Graphics.cpp

libs/hwui/jni/GraphicsJNI.h

libs/hwui/jni/Paint.cpp