[FM] FM will not resume playing after replugging in headphones

Launch FM and play -> Tap more button and select
"Start recording" -> Plug out headphones while
recording -> Plug in headphones and check the
audio -> Tap "Save" button and check the audio
-> Tap play button and check the audio, FM can not
resume playing after step 4(5 and 6).

The fix is to add FmRecordActivity foreground control.

Bug 18794870

https://partner-android-review.git.corp.google.com/#/c/189795/



Change-Id: I565c641413836f34c88e2643afd9972f198177da
Signed-off-by: Benson Huang <benson.huang@mediatek.com>