Fix ImpossibleNullComparison errorprone warning

Protobuf fields cannot be null.

Bug: 253827323
Test: m RUN_ERROR_PRONE=true javac-check
Change-Id: Ied830dbf9ddde4c43281feb38a01f01d0750fea7

src/com/android/settings/fuelgauge/batteryusage/bugreport/BatteryUsageLogUtils.java

@@ -95,7 +95,7 @@ public final class BatteryUsageLogUtils {
                         .append(ConvertUtils.utcToLocalTimeForLogging(entry.getTimestamp()))
                         .append(" " + entry.getAction());
         final String description = entry.getActionDescription();
-        if (description != null && !description.isEmpty()) {
+        if (!description.isEmpty()) {
             builder.append(" " + description);
         }
         return builder.toString();