Fix identity decoration unit tests to pass in S-on-R

Add S checks around all set/get identity decoration API in
unitests to avoid failing tests in S-on-R.

Bug: 182905625
Test: atest com.android.server.wifi android.net.wifi
Test: atest PasspointConfigurationTest PpsMoParserTest
Change-Id: Icc56ad6ea946e625329e8e716e86ade1931bfaaf
4 files changed