Add info that flashing AB zip will flash to the inactive slot

Also inform user, that a reboot is required to switch slots

Change-Id: I7d609ee3d231e5d38d9145962e979e012d9a0ac8
(cherry picked from commit 5343a3ca2afcdd895677c5c3ff16a83af372c7b7)
diff --git a/gui/theme/common/languages/en.xml b/gui/theme/common/languages/en.xml
index 3769da5..ac9472e 100755
--- a/gui/theme/common/languages/en.xml
+++ b/gui/theme/common/languages/en.xml
@@ -722,5 +722,7 @@
 		<string name="unmount_sys_install">Unmount System before installing a ZIP</string>
 		<string name="unmount_system">Unmounting System...</string>
 		<string name="unmount_system_err">Failed unmounting System</string>
+		<string name="flash_ab_inactive">Flashing A/B zip to inactive slot: {1}</string>
+		<string name="flash_ab_reboot">To flash additional zips, please reboot recovery to switch to the updated slot.</string>
 	</resources>
 </language>
diff --git a/twinstall.cpp b/twinstall.cpp
index 4143cf2..b550be1 100755
--- a/twinstall.cpp
+++ b/twinstall.cpp
@@ -443,6 +443,7 @@
 	} else {
 		if (Zip.EntryExists(AB_OTA)) {
 			LOGINFO("AB zip\n");
+			gui_msg(Msg(msg::kHighlight, "flash_ab_inactive=Flashing A/B zip to inactive slot: {1}")(PartitionManager.Get_Active_Slot_Display()=="A"?"B":"A"));
 			// We need this so backuptool can do its magic
 			bool system_mount_state = PartitionManager.Is_Mounted_By_Path(PartitionManager.Get_Android_Root_Path());
 			bool vendor_mount_state = PartitionManager.Is_Mounted_By_Path("/vendor");
@@ -457,6 +458,7 @@
 				PartitionManager.UnMount_By_Path("/vendor", true);
 			if (!system_mount_state)
 				PartitionManager.UnMount_By_Path(PartitionManager.Get_Android_Root_Path(), true);
+			gui_warn("flash_ab_reboot=To flash additional zips, please reboot recovery to switch to the updated slot.");
 
 		} else {
 			if (Zip.EntryExists("ui.xml")) {