Merge changes If034479e,I016852b5,If556d1e6,Ic181ee92,Ic47760f7, ... into studio-master-dev

* changes:
  android-configure.sh: Add ccache support to --mingw builds.
  android-configure.sh: Remove TARGET_OS variable.
  android-configure.sh: Rename CPU to BUILD_ARCH
  android-configure.sh: Remove HOST_BIGENDIAN probe.
  android-configure.sh: Minor reformatting.
  Remove obsolete android/config/ directories.
  android-configure.sh: Simplify script.