Immutable. The revision ID of the phrase matcher. A new revision is committed whenever the matcher is changed, except when it is activated or deactivated. A server generated random ID will be used. Example: locations/global/phraseMatchers/my-first-matcher@1234567
The role whose utterances the phrase matcher should be matched against. If the role is ROLE_UNSPECIFIED it will be matched against any utterances in the transcript.