Camera2: Fix derped mismerge

When attempting to merge https://github.com/CyanogenMod/android_packages_apps_Camera2/commit/3c0af9d96e308bc276c88afb95df5aa5146016a4

(see https://github.com/omnirom/android_packages_apps_Camera2/commit/31dc2d3facd7cfcb6e354b70833a1c1985e2518b )

Bad Things happened.

usePreferredPreviewSizeForEffects is obsolete and deprecated AND in addition the logic was inverted...

Thanks go to Andrew Jiang for finding the error while reviewing the broken code.

Fixes:
http://jira.omnirom.org/browse/OMNI-255
http://jira.omnirom.org/browse/OMNI-738
http://jira.omnirom.org/browse/OMNI-387

Change-Id: I15c0a7c10c83d459587fc978657d84a50f568ff1