Rename Metering to Telemetry in common guide.

backport: havana

Renamed section_getstart_metering.xml to section_getstart_telemetry.xml

Change-Id: I583524b7e5cbea48579482cca02753166c186622
(cherry picked from commit 3138f6fc0ae27fe88348688df24728d7a7432881)
Merge "Rename Metering to Telemetry in common guide." into stable/havana