Fix `userDidSubmitInput` getting called multiple times after a search request is submitted

[FrankElias77]

Bug Report

When the user submit a search request through a searchableChoiceSet, the userDidSubmitInput keyboard's delegate method gets called multiple times in case the updateAutocomplete method is implemented

Reproduction Steps

1. Present a searchable choice set
2. Submit a search through the search box in choice set or click on an autocomplete cell

Expected Behavior

userDidSubmitInput method gets called once with source .submitted

Observed Behavior

userDidSubmitInput method gets called multiple times with source .submitted

OS & Version Information

• iOS Version: 15.0
• SDL iOS Version: 7.3.0
• Testing Against: SYNC 3.0

[theresalech]

Closed via #2065