Bug 993958 - [System] Fix running the unit tests in B2G Desktop r=alive
Bug 987437 - FM Radio Unit Tests fails on B2G Desktop r=timdream

Add a fake mozSettings at global level to prevent init from running at an
awkward moment.
Merge pull request #18131 from julienw/987437-fmradio-tests

Bug 987437 - FM Radio Unit Tests fails on B2G Desktop r=timdream
Merge pull request #18108 from julienw/993958-fix-system-test-in-b2g-desktop

Bug 993958 - [System] Fix running the unit tests in B2G Desktop r=alive
Bug 973445 - [settings] refactor Sound panel with AMD pattern
add tone tests