Add a log message if enabling Ethernet tethering if it is already enabled.

Test: builds
Bug: 150644681
Change-Id: I68123e6dd04ccae5da2ecd7526c11d9f835d1d57
Merged-In: I68123e6dd04ccae5da2ecd7526c11d9f835d1d57
(cherry picked from commit e6b8ded8121c137a7e434e1c2a9e04cc144f2f28)
1 file changed