Mobile: Add 120 frame rate option

[ChrisNZL]

In 0.3.7, believe the mobile frame rate is capped @ 60 FPS as an arbitrary number.

Report on Android that user has 120 Hz available in their screen resolutions, but 60 FPS is the highest option in the Target Frame Rate list.

(there is Maximum as an option, but would be nice to explicitly list 120 above 60)

Feedback ID 0.3.6c_20221022-DCRTG:

the options has 120fps listed under Resolution but I can only select 60fps as an option in FPS. I have a Samsung Fold 4.

Potentially can be enabled on iPad too, as some iPads use 120 Hz.

Tasks:

• [x] Add 120 as an option under Target Frame Rate.
• [ ] See about determining the highest frame rate via looking at the game's list of screen resolutions' refresh rates.

[ChrisNZL]

Added in 0.3.7b.