[mobile] request layout when size changes

The bug: the stacked mobile icon's outer view was not re-measuring when
the inner compose view changed width. Therefore, the icon was sometimes
clipped.

The fix: request layout when the size changes.

Test: manual; have 2 real, working SIMS, turn off wi-fi and toggle
airplane mode from the settings app. If the stacked mobile view comes
back and properly shows the RAT indicator (e.g., 5G) without any
clipping, then it's fixed.
Fixes: 406832105
Flag: com.android.settingslib.flags.new_status_bar_icons
Flag: com.android.systemui.status_bar_root_modernization

Change-Id: I49922bde8d13b218bbf244baaf0abf772a7deda3