Fix WebRTC JNI error when rolling Chromium.

With the landing of crrev.com/c/2364635, WebRTC has the below compile error when rolling chromium.
ci.chromium.org/p/webrtc/builders/try/android_arm64_rel/40012
'base::android::JNI_TraceEvent_StartATrace' has internal linkage but is not defined
'base::android::JNI_TraceEvent_SetupATraceStartupTrace' has internal linkage but is not defined

The error doesn't occur for functions like JNI_TraceEvent_BeginToplevel hence the proposed fix.

Bug: 1095587
Change-Id: Iaf2cc152883ff7b991ce0567577bf937e634d2de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2370622
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801071}

base/android/trace_event_binding.cc

@@ -77,11 +77,11 @@ static void JNI_TraceEvent_RegisterEnabledObserver(JNIEnv* env) {
   base::android::Java_TraceEvent_setEnabled(env, false);
 }
 static void JNI_TraceEvent_StartATrace(JNIEnv* env,
-                                       base::android::JavaParamRef<jstring>&) {}
+                                       const JavaParamRef<jstring>&) {}
 static void JNI_TraceEvent_StopATrace(JNIEnv* env) {}
 static void JNI_TraceEvent_SetupATraceStartupTrace(
     JNIEnv* env,
-    base::android::JavaParamRef<jstring>&) {}
+    const JavaParamRef<jstring>&) {}
 
 #endif  // BUILDFLAG(ENABLE_BASE_TRACING)