Add proto dump flag to services (1/2)

Adds new PROTO flag which requests services to dump sections
in proto format. Modifies dumpsys to take in proto argument
and pass on proto flags to services which support proto
dumps. Modify PriorityDumper helper class to parse proto
arguments and set asProto flags.

Bug: 67716082

Test: mmm -j56 frameworks/native/cmds/dumpsys && \
      mmm -j56 frameworks/native/services/utils && \
      adb sync data && \
      adb shell /data/nativetest/dumpsys_test/dumpsys_test && \
      adb shell /data/nativetest64/dumpsys_test/dumpsys_test && \
      adb shell /data/nativetest/prioritydumper_test/prioritydumper_test && \
      adb shell /data/nativetest64/prioritydumper_test/prioritydumper_test && \
      printf "\n\n#### ALL TESTS PASSED ####\n"

Change-Id: I42c2a6a8876efbf9a7d792d68572499b16985147