Update README and CHANGELOG for RKP

Bug: 254112961
Test: vts_treble_vintf_vendor_test
Merged-In: Ib66fcbdbaadda3f32cd8423f61bd31d5f43dc44b
Change-Id: Ib66fcbdbaadda3f32cd8423f61bd31d5f43dc44b
3 files changed