Mark the logging heap read-only to media.log service

Change-Id: Ie26a9e7e37c951774c71d2c53886db52dd5479aa
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 50179c5..c62c627 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -173,7 +173,7 @@
     char value[PROPERTY_VALUE_MAX];
     bool doLog = (property_get("ro.test_harness", value, "0") > 0) && (atoi(value) == 1);
     if (doLog) {
-        mLogMemoryDealer = new MemoryDealer(kLogMemorySize, "LogWriters");
+        mLogMemoryDealer = new MemoryDealer(kLogMemorySize, "LogWriters", MemoryHeapBase::READ_ONLY);
     }
 #ifdef TEE_SINK
     (void) property_get("ro.debuggable", value, "0");