📋 Change Webapp Install field trial names.

Bug: 937871
Change-Id: I95efef32433b0daab3b62d55f427e8b883d3917b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1751731
Auto-Submit: Peter Conn <peconn@chromium.org>
Commit-Queue: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686542}

testing/variations/fieldtrial_testing_config.json

@@ -99,7 +99,7 @@
             ],
             "experiments": [
                 {
-                    "name": "InstallApp",
+                    "name": "Install app",
                     "params": {
                         "include_no_download_required": "false"
                     },
@@ -108,7 +108,7 @@
                     ]
                 },
                 {
-                    "name": "InstallAppNoDownloadRequired",
+                    "name": "Install app (no download required)",
                     "params": {
                         "include_no_download_required": "true"
                     },