WifiManagerTest: test for startLOHS return code

Add a test checking the return code value for startLocalOnlyHotspot.
This test verifies that the error code supplied by WifiServiceImpl is
passed to the caller via the onFailed(reason) callback.

Bug: 36760523
Test: frameworks/base/wifi/tests/runtests.sh
Change-Id: I37eb788d62df89e0b2a133be4368a375e29e39e3
1 file changed