Add protobuf dumpsys of connmetrics. Primarily used by incident service
to capture an incident report proto.
Command to invoke (any of the following after lunch and env setup):
$ adb shell dumpsys contexthub --proto
$ adb shell incident 3051
$ incident_report 3051
Bug: 146086599
Test: $ incident_report 3051, then compare the content with "dumpsys
contexthub"
Change-Id: I6c2ed76a1a17f9bfc60d07e68cd66d5eea00e9b0