Add apache-xml elements to the core APIs

See the associated change in external/apache-xml for
full details.

This change adds apache-xml source to the core_api_files
filegroup to include them in the core API files.

Bug: 113148576
Test: build
Change-Id: I2e2dbe15d675bd21b8e0a3a8c8e8763d254851fc
1 file changed