Update Android 12 support for stable SDK 31

Android 12's SDK is now versioned as 31, so it no longer needs to be
special-cased.

customize.sh

@@ -11,10 +11,6 @@ fi
 
 sdk="$(getprop ro.build.version.sdk)"
 version="$(getprop ro.vendor.build.version.release)"
-if getprop ro.build.id | grep -q SPB2; then
-    sdk=31-b2
-    version="12 Beta 2"
-fi
 
 # Initial version check; version can be changed later.
 if [[ ! -d "$MODPATH/system_sdk$sdk" ]]; then

post-fs-data.sh

@@ -5,10 +5,6 @@ MODPATH="/data/adb/modules/safetynet-fix"
 # Get runtime version
 sdk="$(getprop ro.build.version.sdk)"
 version="$(getprop ro.vendor.build.version.release)"
-if getprop ro.build.id | grep -q SPB2; then
-    sdk=31-b2
-    version="12 Beta 2"
-fi
 
 # Prepare to update version
 rm -fr "$MODPATH/system"

service.sh

@@ -2,7 +2,8 @@
 
 # Keystore v2 starts before Magisk on Android 12, so it needs to be restarted.
 # Do this in service.sh to make sure that files have been mounted already.
-if getprop ro.build.id | grep -q SPB2; then
+sdk="$(getprop ro.build.version.sdk)"
+if [[ "$sdk" -ge 31 ]]; then
     stop keystore2
     start keystore2
 fi