Add field trial testing config for frecency ranking of local history ZPS

A previous CL with the same title added trial testing config for Desktop
only. This CL adds the same config for Android.

Prestable experiment: http://shortn/_ZyDTi78UyT

Bug: 1096615
Change-Id: I2fb5b8752b814d70e1ad549f95381e3c9aa17947
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2575041Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834367}

testing/variations/fieldtrial_testing_config.json

@@ -4847,6 +4847,7 @@
                 {
                     "name": "AndroidExperiments",
                     "params": {
+                        "OmniboxLocalZeroSuggestAgeThreshold": "7",
                         "OmniboxMaxURLMatches": "7",
                         "OmniboxMaxZeroSuggestMatches": "15",
                         "UIMaxAutocompleteMatches": "8",
@@ -4855,6 +4856,8 @@
                     "enable_features": [
                         "OmniboxAdaptiveSuggestionsCount",
                         "OmniboxCompactSuggestions",
+                        "OmniboxLocalZeroSuggestAgeThreshold",
+                        "OmniboxLocalZeroSuggestFrecencyRanking",
                         "OmniboxMaxURLMatches",
                         "OmniboxMaxZeroSuggestMatches",
                         "OmniboxOnFocusSuggestionsContextualWebOnContent",