Setup wear credential manager enabled flag within trunk

This sets up wear credential manager enabled flags configuration within the trunk directories.

DD: go/wear-dd-credential-manager
Bug: 301168341
Tested: enable/disabled flag with adb command and reboot the system, ·getSystemService("credential")· returns non-null/null result correspondingly.
Change-Id: I412eb67cead197998134b7d23c706c37d9e0a848