Enable OomIntervention purge v8 by default

This CL enables OomIntervention purge v8 feature by default.
This used to be overridden by Finch and was made true for 100%.

bug: 
Change-Id: I4a10ffa4b128d8d7acfb13bba57c2e2f42843201
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1784024Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Keishi Hattori <keishi@chromium.org>
Commit-Queue: Yuzu Saijo <yuzus@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693045}

chrome/browser/android/oom_intervention/oom_intervention_config.cc

@@ -125,7 +125,7 @@ OomInterventionConfig::OomInterventionConfig()
   is_navigate_ads_enabled_ = base::GetFieldTrialParamByFeatureAsBool(
       features::kOomIntervention, kNavigateAdsParamName, true);
   is_purge_v8_memory_enabled_ = base::GetFieldTrialParamByFeatureAsBool(
-      features::kOomIntervention, kPurgeV8MemoryParamName, false);
+      features::kOomIntervention, kPurgeV8MemoryParamName, true);
   should_detect_in_renderer_ = base::GetFieldTrialParamByFeatureAsBool(
       features::kOomIntervention, kShouldDetectInRenderer, true);