Fix broken StringBuilder construction.

StringBuilder doesn't have a char constructor and so passing a char calls the
int constructor that presizes the StringBuilder rather than creating it
containing a single character.
This bug was caught by error prone.

Change-Id: I809ce0fcf930688db925ac7a8e23ee85086d479e
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ServiceMonitor.java b/packages/SystemUI/src/com/android/systemui/statusbar/ServiceMonitor.java
index 602989a..db46dc6 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ServiceMonitor.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ServiceMonitor.java
@@ -272,7 +272,7 @@
 
     private static String bundleToString(Bundle bundle) {
         if (bundle == null) return null;
-        StringBuilder sb = new StringBuilder('{');
+        StringBuilder sb = new StringBuilder("{");
         for (String key : bundle.keySet()) {
             if (sb.length() > 1) sb.append(',');
             Object v = bundle.get(key);