This change removes the size of the Android binary by around 5MB and decreases our build time for all platforms.
- Remove C++ runtime static dependency on Android by changing Xerces to be a subtree instead of a submodule.
- Subtree made from Xerces repo tag Xerces-C_3_2_0 commit dffc3028df8ea44985c92f2df28115860e39e344
- Changes to Xerces to avoid using mblen and use mbrlen to be able to compile for Android API level 19
- Adds switch to build Xerces tests and samples (OFF by default)
- Changes AOSP scripts to build for level 19
Related work items: #15424024
Ruben Guerrero Samaniego