SDK Parcelables: @JavaOnlyStableParcelable

Now that androidx is using these more for SDK sandbox and usage
of stable AIDL is generally on the rise, go ahead and mark all
platform Parcelables as stable.

This is okay because all apps will share their definition from the
common BCP. If this is ever used on Parcelables not on the common
BCP, that may cause version mismatch and break usage of stable
AIDL that uses these interfaces.

Bug: 258850063
Test: build
Change-Id: Iba43040beda379f0735adf1af319a1dbfce99447