BatteryStats: Adds an additional condition to avoid

ArrayIndexOutOfBounds.

This change takes care of the case when the length
of the array is 0.

Bug: 16039301
Change-Id: Ideb3ccc723c5d720069760aeedae8abb91c6420d

core/java/com/android/internal/os/PowerProfile.java

@@ -251,7 +251,7 @@ public class PowerProfile {
                 final Double[] values = (Double[]) data;
                 if (values.length > level && level >= 0) {
                     return values[level];
-                } else if (level < 0) {
+                } else if (level < 0 || values.length == 0) {
                     return 0;
                 } else {
                     return values[values.length - 1];