scripts: refactor and major addon.d fixes

- remove redundant addon.d.sh script bits that were covered elsewhere ($TMPDIR in util_functions.sh, find_dtbo_image in patch_dtbo_image)
- refactor addon.d.sh and flash_script.sh for simplicity and readability, and put common flashing script in util_functions.sh (as patch_boot_image), which should greatly help avoid them getting out of sync going forward and fixes compressing ramdisk support and post-patch cleanup for addon.d
- add check_data to addon.d.sh since moving stock_boot* and stock_dtbo* backups depend on it and so weren't occuring with addon.d
- fix find_manager_apk with working fallback for recovery addon.d execution (where `magisk --sqlite` will not work for hidden Manager), Manager DynAPK hiding, and print a useful log warning if an APK can't be found

scripts/flash_script.sh

@@ -1,7 +1,7 @@
 #MAGISK
 ##########################################################################################
 #
-# Magisk Flash Script
+# Magisk Flash Script (updater-script)
 # by topjohnwu
 #
 # This script will detect, construct the environment for Magisk
@@ -103,43 +103,10 @@ fi
 $BOOTMODE || recovery_actions
 
 ##########################################################################################
-# Boot patching
+# Boot/DTBO Patching
 ##########################################################################################
 
-eval $BOOTSIGNER -verify < $BOOTIMAGE && BOOTSIGNED=true
-$BOOTSIGNED && ui_print "- Boot image is signed with AVB 1.0"
-
-SOURCEDMODE=true
-cd $MAGISKBIN
-
-$IS64BIT && mv -f magiskinit64 magiskinit || rm -f magiskinit64
-
-# Source the boot patcher
-. ./boot_patch.sh "$BOOTIMAGE"
-
-ui_print "- Flashing new boot image"
-
-if ! flash_image new-boot.img "$BOOTIMAGE"; then
-  ui_print "- Compressing ramdisk to fit in partition"
-  ./magiskboot cpio ramdisk.cpio compress
-  ./magiskboot repack "$BOOTIMAGE"
-  flash_image new-boot.img "$BOOTIMAGE" || abort "! Insufficient partition size"
-fi
-
-./magiskboot cleanup
-rm -f new-boot.img
-
-if [ -f stock_boot* ]; then
-  rm -f /data/stock_boot* 2>/dev/null
-  $DATA && mv stock_boot* /data
-fi
-
-$KEEPVERITY || patch_dtbo_image
-
-if [ -f stock_dtbo* ]; then
-  rm -f /data/stock_dtbo* 2>/dev/null
-  $DATA && mv stock_dtbo* /data
-fi
+patch_boot_image
 
 cd /
 # Cleanups