Explicitly link libstdc++.a for static gtest executables.
Explicitly link libstdc++.a for static gtest executables.

Change-Id: I29e3a4036264acd00dfa3229c9d0fc52ee20830e

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build