Themes: Clear out bootanimation if pkgName empty

An empty string for the package name implies the given component
should be cleared out, so make sure updateBootAnim respects that.

Change-Id: I07c7fc64970546c2d73a610d9c0b71f1e757657d
TICKET: CRACKLING-1043
diff --git a/cm/lib/main/java/org/cyanogenmod/platform/internal/ThemeManagerService.java b/cm/lib/main/java/org/cyanogenmod/platform/internal/ThemeManagerService.java
index 8c0af4c..7b6054c 100644
--- a/cm/lib/main/java/org/cyanogenmod/platform/internal/ThemeManagerService.java
+++ b/cm/lib/main/java/org/cyanogenmod/platform/internal/ThemeManagerService.java
@@ -590,7 +590,7 @@
     }
 
     private boolean updateBootAnim(String pkgName) {
-        if (SYSTEM_DEFAULT.equals(pkgName)) {
+        if (TextUtils.isEmpty(pkgName) || SYSTEM_DEFAULT.equals(pkgName)) {
             clearBootAnimation();
             return true;
         }