Better way to override NDK_TOOLCHAIN_VERSION at command line

Additional fix to previous one 47b0797d5f6f96955fb02312b03828676081be6b
1) Really change chang -> clang3.2 from command line now
2) Other than translation in 1), don't change NDK_TOOLCHAIN_VERSION
   to 3.1 or 3.2, because test like flto identify clang in
   NDK_TOOLCHAIN_VERSION and do different things

Change-Id: Iac96e71e3e95116e8dec49a325fd7260e20b4fae
1 file changed