Proto message for "dumpsys sensorservice --proto"

Add SensorServiceProto for protobuf dumpsys of sensorservice. Primarily
used by incident service to capture an incident report proto.
Also add a gensrc rule to generate cpp headers of frameworks proto to
be used by native services like sensorservice. Added "static" qualifier
to a few generated fields in the header to avoid linker conflict.

Command to invoke (any of the following after lunch and env setup):
$ adb shell dumpsys sensorservice --proto
$ adb shell incident 3053
$ incident_report 3053

Bug: 146086105
Test: Execute the above commands and compare the output against dumpsys
      sensorservice

Change-Id: I282ff37bd3e845464d0693d69fc0d82943cc9855