[Ravenwood] Copy font and ICU data into ravenwood-runtime

We need to put font and data file references into filegroups with the
proper variant and reference it in android_ravenwood_libgroup { data } and android_ravenwood_libgroup { font }, or else soong will complain about mismatching variants when building if we directly reference these modules.

Bug: 337110712
Flag: EXEMPT host side change only
Test: $ANDROID_BUILD_TOP/frameworks/base/ravenwood/scripts/run-ravenwood-tests.sh
Change-Id: Ie2d537eb0412fef573213e27806022a01651f43e