make recovery UI images more general; allow for installation animation

Change some of the UI parameters (# of indeterminate progress bar
frames, fps, etc.) from #defined constants to variables that can be
set by the device-specific recovery_ui code (via a new function).

Support overlaying different images on top of the base installation
icon to animate it.  Make the FPS control more accurate.

Change-Id: I9268b389b7ea6b3ed9e0c7eae37baf4272e60edd
diff --git a/default_recovery_ui.c b/default_recovery_ui.c
index bcba888..7c4017e 100644
--- a/default_recovery_ui.c
+++ b/default_recovery_ui.c
@@ -29,6 +29,9 @@
                        "wipe cache partition",
                        NULL };
 
+void device_ui_init(UIParameters* ui_parameters) {
+}
+
 int device_recovery_start() {
     return 0;
 }