Bug 1450787 - Disable javascript.options.gc_on_memory_pressure pref on Android. r=smaug

This pref was enabled on Android Nightly and an increase in the background CPU consumption was observed. This change backs it out to investigate the performance impact more.

Differential Revision: https://phabricator.services.mozilla.com/D221122

modules/libpref/init/StaticPrefList.yaml

@@ -8123,13 +8123,10 @@
 # appropriate pref is set.
 - name: javascript.options.gc_on_memory_pressure
   type: bool
-#if defined(MOZ_WIDGET_ANDROID)
-  # We will enable the JS engine's GC on memory pressure on Nightly to observe its performance
-  # impact and then decide to ride the trains or not. See bug 1450787.
-  value: @IS_NIGHTLY_BUILD@
-#else
-  value: true
-#endif
+  # Disable the JS engine's GC on memory pressure on Android for now to continue investigating its
+  # performance impacts and then decide to enable it or not.
+  # See bug 1450787.
+  value: @IS_NOT_ANDROID@
   mirror: always
 
 # We allow at most MIN(max, MAX(NUM_CPUS / cpu_divisor, 1)) concurrent GCs