Add an agent to enable VLOG options

We added the ability to manipulate the 'VLOG' (-verbose:...) options
at runtime a while ago. This adds an agent which can be loaded to
change these after starting an app. This can be useful for debugging.

Test: m libenablevlogs
      adb push $ANDROID_PRODUCT_OUT/system/lib/libenablevlogs.so /data/local/tmp
      adb shell run-as com.antonioleiva.bandhookkotlin cp /data/local/tmp/libenablevlogs.so ./code_cache
      adb shell cmd activity attach-agent com.antonioleiva.bandhookkotlin /data/data/com.antonioleiva.bandhookkotlin/code_cache/libenablevlogs.so=class,jit
      adb logcat
Change-Id: I80a97684b19ffc81f6e1181fc15f24cf3b53c31b
4 files changed