Add MyRoboTest into TEST_MAPPING

We create a test group my-robo-presubmit to demonstrate tests can be grouped in the granularity we wanted to group them.

Bug: 333895151
Change-Id: I97b5919a1637fc0dfde5209e7eae54c479582e22
Signed-off-by: Weijia He <hwj@google.com>
Test: abtd
1 file changed