Fix the option to set a different screen lock in the "Set a PIN"

screen is displayed off the screen when the device language is set
to Arabic

To call optButton's MarginLayoutParams setMarginStart() instead of
set leftMargin.

Flag: EXEMPT bugfix

Bug: 355422248

Test: build Forrest ROM and verify the UI
Change-Id: I700b83937ecd8509864fa3c80826de0ba0437ca2