Fenix: FNX2-15453 ⁃ Clean up incorrect XML uses of `@+id`

[NotWoods]

In our XML files there are two similar ways to refer to IDs: @+id/example_id and @id/example_id. The "plus" variant should only be used to create a new ID, and should only be used inside android:id.

In other attributes, the ID is used to reference another value (such as app:destination, app:layout_constraintStart_toStartOf). In these locations, the @id variant with no plus should be used. Incorrect usage doesn't have runtime issues, but makes the IDE confused sometimes.

We may want to create a lint rule for this later on.

[leonardoamurca]

Hi @NotWoods! Can I help you with these changings as my good first issue ?

[NotWoods]

Sure @leonardoamurca! Please look through our docs so you can check out a copy of the codebase locally and edit it with Android Studio. Let me know if you need tips for how to proceed with the changes.

[NotWoods]

Closing since this has been fixed by @leonardoamurca 😄