Iron-a11y-keys-behavior catches keyboard events globally. Some keyboard
events must be scoped to a component level (e.g. `enter`) in order to
not override native browser functionality (link navigation, screen
reader behavior).
Bug: Issue 7277
Change-Id: I3e92c3fbffb6cdc2848c4fc6d450cf1cb075f257
(cherry picked from commit e5bc78a4c5)