Do not trigger a disk write violation during dumpsys gfxinfo

Writing to a pipe FD here is okay because it doesn't write to
the physical disk.

Bug: 203682422
Test: dumpsys gfxinfo
Change-Id: Ibb484f0d466d13e55d2c8059a5af964641281110

core/java/android/app/ActivityThread.java

@@ -4645,12 +4645,14 @@ public final class ActivityThread extends ClientTransactionHandler
     }
 
     private void handleDumpGfxInfo(DumpComponentInfo info) {
+        final StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
         try {
             ThreadedRenderer.handleDumpGfxInfo(info.fd.getFileDescriptor(), info.args);
         } catch (Exception e) {
             Log.w(TAG, "Caught exception from dumpGfxInfo()", e);
         } finally {
             IoUtils.closeQuietly(info.fd);
+            StrictMode.setThreadPolicy(oldPolicy);
         }
     }