Add support for keyboard prebuilt module type

Add 3 different module type:
 - prebuilt_usr_keylayout
 - prebuilt_usr_keychars
 - prebuilt_usr_idc

Bug: 337998675
Test: cd build/soong/etc ; go test -run \
      TestPrebuiltPrebuiltUserKeyLayoutInstallDirPath
Test: cd build/soong/etc ; go test -run \
      TestPrebuiltPrebuiltUserKeyCharsInstallDirPath
Test: cd build/soong/etc ; go test -run \
      TestPrebuiltPrebuiltUserIdcInstallDirPath
Change-Id: I5bafbc48dd0edd0d06783b89b904330a2a30c743