[devicelab] dont strip symbols in platform views layout test. (flutter#163101)

The hcpp integration test is crashing I'd like to see why and also not
deal with manually downloading symbol files and using ndk-stack.

Since we don't strip the libraries, all we need to do is add a gradle
configuration so that stack traces are readable in the logs.

Author: Jonah Williams

dev/benchmarks/platform_views_layout/android/app/build.gradle

@@ -57,6 +57,10 @@ android {
             signingConfig signingConfigs.debug
         }
     }
+
+    packagingOptions {
+        doNotStrip '**/*.so'
+    }
 }
 
 flutter {