recovery: More refactoring of WearUI

This patch performs the following modifications:
- Remove setBackground function, and currentIcon member variable.
- Remove common Progress*, Redraw and EndMenu functions.

Bug: 27407422
Change-Id: Ic3c0e16b67941484c3bc1d04c9b61288e8896808
Signed-off-by: Prashant Malani <pmalani@google.com>
diff --git a/screen_ui.h b/screen_ui.h
index 08a5f44..386deac 100644
--- a/screen_ui.h
+++ b/screen_ui.h
@@ -68,7 +68,6 @@
     void SetColor(UIElement e);
 
   private:
-    Icon currentIcon;
     int installingFrame;
     const char* locale;
     bool rtl_locale;
@@ -139,6 +138,8 @@
     void LoadBitmap(const char* filename, GRSurface** surface);
     void LoadBitmapArray(const char* filename, int* frames, int* fps, GRSurface*** surface);
     void LoadLocalizedBitmap(const char* filename, GRSurface** surface);
+  protected:
+    Icon currentIcon;
 };
 
 #endif  // RECOVERY_UI_H