Keyguard SIM PIN: Fix height

Some views within the KeyguardSecurityViewFlipper limit their height,
while others do not. When a view is marked as GONE, as when the
ViewFlipper changes the focused child, disregard those views from the
custom max height measurement as not to interfere with normal measurement.

Fixes: 178412096
Test: use password or pattern bouncer, go back to aod/ls, reinsert
locked SIM

Change-Id: I06047bcd8fb7c11eb0bac272f28147e08b18988d