Put tuner scan handling to a thread.

Bug: 210747502
Fix: 210747502
Test: atest android.media.tv.tuner.cts on AIDL and HILD HALs.
Test: atest VtsHalTvTunerTargetTest
Test: atest VtsHalTvTunerV1_1TargetTest
Test: atest VtsHalTvTunerV1_0TargetTest
Change-Id: Iead93df1dc09ef2a047893037ad2345ad4183b1e
4 files changed