Entity selector: Internally used _setEntity method

Setting the selected entity from within the entity selector itself (e.g. by validating the current
input) should not update the actual input value. For example, typing an alias would result in it
being replaced by the label.

Change-Id: I5506271b5a64a5597b3850a3780efe9bcc2c6723
Merge "Entity selector: Internally used _setEntity method"