[RTT] Add shell command for getting RTT capabilities

Retrieve the RTT capabilities using a shell command. Useful for
flagging features for testing.

Note: these are not necessarily represented by APIs since some of
the capability is best effort (e.g. one-sided) or not part of a
public API.

Bug: 119068671
Test: builds, run 'adb shell cmd wifirtt get-cap' - verify o/p.
Change-Id: Iadd37847b785c540ed0cc761f669ddb87341145f
2 files changed