Only ask to start an USBMS session when plugged into a USB host on Kobo (#6645)

* Only ask to start an USBMS session when plugged into a USB host on Kobo

Also, fix a typo that broke plugout detection on cervantes

* Bump base (necessary input/KoboUSBMS changes)

https://github.com/koreader/koreader-base/pull/1183

base

@@ -1 +1 @@
-Subproject commit 8efd649950d296fc79d8ce5ef50060ef815f6f5a
+Subproject commit 7e52fff017742065ef5c99a251461622643dc7cb

frontend/ui/uimanager.lua

@@ -155,6 +155,20 @@ function UIManager:init()
             Device:getPowerDevice():toggleFrontlight()
         end
         self.event_handlers["Charging"] = function()
+            self:_beforeCharging()
+            -- NOTE: Plug/unplug events will wake the device up, which is why we put it back to sleep.
+            if Device.screen_saver_mode then
+                self:suspend()
+            end
+        end
+        self.event_handlers["NotCharging"] = function()
+            -- We need to put the device into suspension, other things need to be done before it.
+            self:_afterNotCharging()
+            if Device.screen_saver_mode then
+                self:suspend()
+            end
+        end
+        self.event_handlers["UsbPlugIn"] = function()
             self:_beforeCharging()
             -- NOTE: Plug/unplug events will wake the device up, which is why we put it back to sleep.
             if Device.screen_saver_mode then
@@ -165,7 +179,7 @@ function UIManager:init()
                 MassStorage:start()
             end
         end
-        self.event_handlers["NotCharging"] = function()
+        self.event_handlers["UsbPlugOut"] = function()
             -- We need to put the device into suspension, other things need to be done before it.
             self:_afterNotCharging()
             if Device.screen_saver_mode then
@@ -322,7 +336,7 @@ function UIManager:init()
                 MassStorage:start()
             end
         end
-        self.event_handlers["USbPlugOut"] = function()
+        self.event_handlers["UsbPlugOut"] = function()
             self:_afterNotCharging()
             if Device.screen_saver_mode then
                 self:suspend()