mItarSpeedLimitExceeded thread safety

Change-Id: Ia8e2378001ba2ffb71925814c95f5a587109c4f3
Fixes: 63941819
Test: Basic build & GPS sanity check
diff --git a/services/core/java/com/android/server/location/GnssLocationProvider.java b/services/core/java/com/android/server/location/GnssLocationProvider.java
index 0aa6a90..e41c17d 100644
--- a/services/core/java/com/android/server/location/GnssLocationProvider.java
+++ b/services/core/java/com/android/server/location/GnssLocationProvider.java
@@ -417,7 +417,11 @@
     // stops output right at 600m/s, depriving this of the information of a device that reaches
     // greater than 600m/s, and higher than the speed of sound to avoid impacting most use cases.
     private static final float ITAR_SPEED_LIMIT_METERS_PER_SECOND = 400.0F;
-    private boolean mItarSpeedLimitExceeded = false;
+
+    // TODO: improve comment
+    // Volatile to ensure that potentially near-concurrent outputs from HAL
+    // react to this value change promptly
+    private volatile boolean mItarSpeedLimitExceeded = false;
 
     // GNSS Metrics
     private GnssMetrics mGnssMetrics;