Suppress output for Protobuf data if Bluetooth is disabled

If Bluetooth is disabled or there is some other error,
don't print anything when extracting the Metrics-related data
in Protobuf format.

[Cherry-pick from AOSP]

Bug: 27315491
Change-Id: Ic1ec5334fbf0b524909400f080e2eac3ec34edf4
1 file changed