Don't specify Mac version for iOS real device tests

Currently all iOS tests can't find a device because Mac versions were updated.
It shouldn't matter what Mac version is used to launch a test on a phone.

TBR: phoglund@webrtc.org
No-Try: True
Bug: None
Change-Id: I1ec3317db4707fb62541302737eed812c5b516a2
Reviewed-on: https://webrtc-review.googlesource.com/90865
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24126}

tools_webrtc/ios/internal.client.webrtc/iOS64_Debug.json

@@ -25,11 +25,7 @@
       "os": "10.3.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13.3",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]

tools_webrtc/ios/internal.client.webrtc/iOS64_Perf.json

@@ -25,11 +25,7 @@
       "os": "11.0.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]

tools_webrtc/ios/internal.client.webrtc/iOS64_Release.json

@@ -26,11 +26,7 @@
       "os": "10.3.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13.3",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]

tools_webrtc/ios/internal.tryserver.webrtc/ios_arm64_dbg.json

@@ -25,11 +25,7 @@
       "os": "10.3.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13.3",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]

tools_webrtc/ios/internal.tryserver.webrtc/ios_arm64_perf.json

@@ -25,11 +25,7 @@
       "os": "11.0.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]

tools_webrtc/ios/internal.tryserver.webrtc/ios_arm64_rel.json

@@ -26,11 +26,7 @@
       "os": "10.3.3",
       "dimensions": [
         {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13.3",
+          "os": "Mac",
           "pool": "Chrome"
         }
       ]