[Ravenwood] Build our own libandroid_runtime

Sometimes we need to customize how we build libandroid_runtime that is
different from layoutlib. Split out all common configurations into its
own cc_defaults and create Ravenwood's own libandroid_runtime module.

Bug: 439059387
Flag: EXEMPT HOST_MODE
Test: f/b/r/scripts/run-ravenwood-tests.sh
Change-Id: Ifb618be581560dc10f4f60eb338930b190380b17