Migrate broadcast radio HAL from HIDL to AIDL

Radio HAL is migrated to AIDL by hidl2aidl tool, and the
following changes are applied:
- Result type is returned as service-specific error than normal
return value since AIDL only allows one return value of primitive
types.
- Integer data types were changed to int, long and byte.
- Constant enum was removed and replaced by constants defined in
IBroadcastRadio.
- Rds and Deemphasis enums were removed and defined as const in
AmFmRegionConfig
- MetadataKey was removed, and Metadata was defined as union.
- ITunerSession:scan() was renamed to ITunerSession:seek().
- ITunerSession was removed and its methods were added to
IBroadcastRadio.
- Callback for config flag setting was added to ITunerCallback.
- Callback and timeout behaviors are clarified.

Bug: 170336130
Test: m -j
Change-Id: Id1cdc5651037429ca07a4d4dc4682709cfc4949b