Don't strip libc++_shared.so.

This will get stripped by gradle before it is included in the user's
APK. Having a non-stripped version in the NDK allows user to debug
libc++ issues, should they be so unfortunate.

Test: ndk/checkbuild.py libc++ && file path/to/libc++_shared.so
Test: Use this NDK in Studio for a CMake project using c++_shared,
    check that the APK has a stripped libc++_shared.so.
Bug: https://github.com/android-ndk/ndk/issues/749

Change-Id: Ifd6972d84c3eceba8dd14f0360033b0516445299
(cherry picked from commit 5dcd3bb23cac63b76acd24bd26f5b9c0dd31e03a)
diff --git a/Android.mk b/Android.mk
index 11c1614..3806bfe 100644
--- a/Android.mk
+++ b/Android.mk
@@ -173,6 +173,7 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := c++_shared
+LOCAL_STRIP_MODE := none
 LOCAL_WHOLE_STATIC_LIBRARIES := c++_static libc++abi
 LOCAL_EXPORT_C_INCLUDES := $(libcxx_export_includes)
 LOCAL_EXPORT_CPPFLAGS := $(libcxx_export_cxxflags)