Default. Update actions insert content at the current cursor position, replacing any selected
content.
INSERT_AT_START
Enum
Update actions insert content at the start of message body.
INSERT_AT_END
Enum
Update actions insert content at the end of the message body. If an email signature is present,
in Gmail on the web, the update action inserts after the user's signature. In the Gmail mobile
app, the update action inserts before the user's signature.
