Fix error regarding .so files

[yehonatan2020]

In vendor/gapps/common/common-vendor.mk building AOSP 12 complains about .so files and just errors out. The fix is as follows:

cc_prebuilt_library_shared +=
vendor/gapps/common/proprietary/product/lib64/libgdx.so:$(TARGET_COPY_OUT_PRODUCT)/lib64/libgdx.so
vendor/gapps/common/proprietary/product/lib/libdmjavaplugin.so:$(TARGET_COPY_OUT_PRODUCT)/lib/libdmjavaplugin.so
vendor/gapps/common/proprietary/product/lib/libdmengine.so:$(TARGET_COPY_OUT_PRODUCT)/lib/libdmengine.so \