An earlier CL with benchmarks has shown that sending strings as UTF-8
is 50% faster for US-ASCII strings, and still 68% faster for complex
strings referencing higher Unicode planes. (So an improvement in
both cases!)
Since code across the OS still makes heavy assumptions about Parcel
strings typically being UTF-16, we need to carefully migrate
Parcelables by hand, which is what this CLs begins doing.
Bug: 154436100
Test: manual
Change-Id: I9a675473e0ce3a4a5c5e305dd851b40bb1560e1c
1639e6b8ee