Add missing unit tests for radio

Unit tests for methods related to discribeContents, parcel, and
creator of classes in radio package were added. The issue that
secondary ids in program selector should not be sorted due to
no comparator implemented was also fixed.

Bug: 249602599
Test: atest android.hardware.radio.tests.unittests
Change-Id: I97b5efe244f1ae0fb37e3e4dd312f4bef6e75d04