Add unit test for TelemetryService

Add test case for handleTelemetryServiceGet function to verify the
static attributes returned by the TelemetryService endpoint

The test validates the following response fields:
- @odata.type and @odata.id
- Id and Name
- Navigation properties: MetricReportDefinitions, MetricReports and
  Triggers

Tested
- All assertions passed

Change-Id: Ibc71ad9ff1796b90fed19d25be1525204919fa04
Signed-off-by: Ramya Sivakumar <sramya@ami.com>