ADB Backup: add ability for TWRP GUI to restore

Restore adb backup files that TWRP made to your PC.
Put files in your backup directory to see them.

e.g. /sdcard/TWRP/BACKUPS/<sn>

Change-Id: I2c57970d77b64c39a302159041456e761c185259
diff --git a/gui/theme/common/portrait.xml b/gui/theme/common/portrait.xml
index f163bea..0d1d6d8 100644
--- a/gui/theme/common/portrait.xml
+++ b/gui/theme/common/portrait.xml
@@ -2209,7 +2209,7 @@
 			<fileselector>
 				<placement x="%indent%" y="%row3_y%" w="%content_width%" h="%fileselector_install_height%"/>
 				<text>{@restore_sel_pack_fs=Select Package to Restore:}</text>
-				<filter folders="1" files="0" nav="0"/>
+				<filter folders="1" files="1" nav="0" extn=".ab"/>
 				<path name="tw_backups_folder"/>
 				<data name="tw_restore" default=""/>
 				<selection name="tw_restore_name"/>
@@ -2429,6 +2429,7 @@
 			</partitionlist>
 
 			<checkbox>
+				<condition var1="tw_enable_adb_backup" op="=" var2="0"/>
 				<placement x="%indent%" y="%row17_y%"/>
 				<text>{@restore_enable_digest_chk=Enable Digest Verification of Backup Files}</text>
 				<data variable="tw_skip_digest_check"/>