ISS: fix exceptions forwarded from ISS to ISSM

fixing b/433697078#comment28

RemoteException can't be forwarded. Swtiched to use forwardable
exceptions in
https://source.corp.google.com/h/googleplex-android/platform/superproject/main/+/main:frameworks/base/core/java/android/os/Parcel.java;l=3181;drc=c4caa45c4c827200ca61d59539f62fb10b4eeb9a

Bug: 433697078
Test: manually introduced exceptions to verify it's forwarded correctly
Test: atest AppSearchSessionCtsTest
Test: atest --rebuild-module-info CtsAppSearchTestCases AppSearchServicesTests
      AppSearchMockingServicesTests AppSearchCoreTests
Flag: com.android.appsearch.flags.enable_isolated_storage
Change-Id: Ifebcdb30e7e326c501c897916fe790e6184a548e
2 files changed