Update and clean up QuietNotificationPrompts fieldtrial configs

Cleaned up the separated Android field trial testing config for enabling
the In Product help UI, and merged it into the QuietNotificationPrompts
field trial, as both the features are being tested together, and there
is currently no need for separate, per-platform configs (the IPH config
is simply ignored on Desktop anyway).

Bug: 1032202
Change-Id: I1bbbadc460bdc3b371941164f415ec06c1c78d7b
TBR: rkaplow@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2061153
Commit-Queue: Kamila Hasanbega <hkamila@google.com>
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746754}

testing/variations/fieldtrial_testing_config.json

@@ -294,26 +294,6 @@
             ]
         }
     ],
-    "AndroidInProductHelpQuietNotificationPrompts": [
-        {
-            "platforms": [
-                "android"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "params": {
-                        "availability": "any",
-                        "event_trigger": "name:tabgroups_dummy;comparator:any;window:1;storage:1",
-                        "event_used": "name:tabgroups_dummy;comparator:any;window:1;storage:1"
-                    },
-                    "enable_features": [
-                        "IPH_QuietNotificationPrompts"
-                    ]
-                }
-            ]
-        }
-    ],
     "AndroidInlineUpdateFlowStudy": [
         {
             "platforms": [
@@ -3941,21 +3921,6 @@
             ]
         }
     ],
-    "Precache": [
-        {
-            "platforms": [
-                "android"
-            ],
-            "experiments": [
-                {
-                    "name": "EnabledCGRUV20b",
-                    "params": {
-                        "config_url": "https://www.gstatic.com/chrome/wifiprefetch/precache_config_g20"
-                    }
-                }
-            ]
-        }
-    ],
     "PreconnectOnDidFinishNavigation": [
         {
             "platforms": [
@@ -4256,10 +4221,15 @@
                 {
                     "name": "EnableWithAdaptiveActivation",
                     "params": {
+                        "availability": "any",
                         "enable_adaptive_activation": "true",
-                        "enable_crowd_deny_triggering": "true"
+                        "enable_crowd_deny_triggering": "true",
+                        "event_trigger": "name:tabgroups_dummy;comparator:any;window:1;storage:1",
+                        "event_used": "name:tabgroups_dummy;comparator:any;window:1;storage:1",
+                        "session_rate": "any"
                     },
                     "enable_features": [
+                        "IPH_QuietNotificationPrompts",
                         "QuietNotificationPrompts"
                     ]
                 }