Refactor InternetIconInjector to SettingsLib

- Plan to share the InternetIconInjector class to System UI.

Bug: 192923176
Test: manual test
make RunSettingsLibRoboTests ROBOTEST_FILTER=WifiUtilsTest

Change-Id: Ieb7080ab6f6462abc3820b47c2a58cc2ea2a083e
Merged-In: Ieb7080ab6f6462abc3820b47c2a58cc2ea2a083e
(cherry picked from commit a9c846a5fae3f531eed5ed3ffe17e3c2efcc65e9)
2 files changed