no-op: Add test to verify legacyTether does not use explicit request

Add a test that verifies that legacyTether will not use the
explicit pending TetheringRequest set by startTethering.

Bug: 216524590
Test: atest TetheringTest
Change-Id: I3e0638a3c60cdf3b73b1accc136ed7098e7b48f6
1 file changed