Add temporary configs for experimental WebRTC waterfall.

This temporary waterfall is because I'm rewriting all the configs while
also porting chromium.webrtc.fyi to LUCI. It will be removed later.

The configs are just copies from chromium.webrtc.fyi.

Bug: 877018
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: Ibe26cdf714a7048f90373dfc0a7eec8ddcead1e2
Reviewed-on: https://chromium-review.googlesource.com/1230023Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Patrik Höglund <phoglund@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592359}

ios/build/bots/chromium.webrtc.fyi.experimental/WebRTC Chromium FYI ios-device.json

+{
+  "comments": [
+    "Builder for 32-bit devices.",
+    "Build is performed with gn+ninja.",
+    "TODO(crbug.com/877018): graduate to chromium.webrtc.fyi when it works."
+  ],
+  "xcode build version": "10a254a",
+  "gn_args": [
+    "additional_target_cpus=[ \"arm64\" ]",
+    "goma_dir=\"$(goma_dir)\"",
+    "ios_enable_code_signing=false",
+    "is_component_build=false",
+    "is_debug=false",
+    "target_cpu=\"arm\"",
+    "target_os=\"ios\"",
+    "use_goma=true"
+  ],
+  "additional_compile_targets": [
+    "all"
+  ],
+  "tests": [
+  ]
+}

ios/build/bots/chromium.webrtc.fyi.experimental/WebRTC Chromium FYI ios-simulator.json

+{
+  "comments": [
+    "Runs tests on @3x, @2x, 64-bit, 32-bit, phone, tablet, iOS 10, and iOS 9.",
+    "TODO(crbug.com/877018): graduate to chromium.webrtc.fyi when it works."
+  ],
+  "xcode build version": "10a254a",
+  "gn_args": [
+    "additional_target_cpus=[\"x86\"]",
+    "goma_dir=\"$(goma_dir)\"",
+    "ios_enable_code_signing=false",
+    "is_component_build=false",
+    "is_debug=true",
+    "symbol_level=1",
+    "target_cpu=\"x64\"",
+    "target_os=\"ios\"",
+    "use_goma=true"
+  ],
+  "additional_compile_targets": [
+    "all"
+  ],
+  "configuration": "Debug",
+  "sdk": "iphonesimulator10.0",
+  "tests": [
+    {
+      "include": "common_tests.json",
+      "device type": "iPhone 6s Plus",
+      "os": "10.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPhone 6s",
+      "os": "10.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPhone 5",
+      "os": "10.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPad Air 2",
+      "os": "10.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPad Retina",
+      "os": "10.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPhone 5",
+      "comments": [
+        "This still relies on system iOS 9.0 legacy simulators,",
+        "since Xcode 8.0 doesn't provide it. But our test runner",
+        "doesn't support Xcode 7.0 anymore..."
+      ],
+      "os": "9.0"
+    },
+    {
+      "include": "common_tests.json",
+      "device type": "iPad Air 2",
+      "os": "9.0"
+    }
+  ]
+}