Extreme battery saver: Remove spammy WTF.

Bug: 68769804
Test: manual test (boot and check logcat)
Change-Id: I3dc0e13a0191f3825f7f5257ae0dd2fdc52d68cc
diff --git a/services/core/java/com/android/server/power/batterysaver/CpuFrequencies.java b/services/core/java/com/android/server/power/batterysaver/CpuFrequencies.java
index 1629486..f248509 100644
--- a/services/core/java/com/android/server/power/batterysaver/CpuFrequencies.java
+++ b/services/core/java/com/android/server/power/batterysaver/CpuFrequencies.java
@@ -54,6 +54,10 @@
             mCoreAndFrequencies.clear();
             try {
                 for (String pair : cpuNumberAndFrequencies.split("/")) {
+                    pair = pair.trim();
+                    if (pair.length() == 0) {
+                        continue;
+                    }
                     final String[] coreAndFreq = pair.split(":", 2);
 
                     if (coreAndFreq.length != 2) {
@@ -65,7 +69,7 @@
                     mCoreAndFrequencies.put(core, freq);
                 }
             } catch (IllegalArgumentException e) {
-                Slog.wtf(TAG, "Invalid configuration: " + cpuNumberAndFrequencies, e);
+                Slog.wtf(TAG, "Invalid configuration: '" + cpuNumberAndFrequencies + "'");
             }
         }
         return this;