Fix SocketsHttpHandler metrics test on Android

[MihaZupan]

Saw failures like these in a few runtime-extra-platforms runs.
My guess is the test ended up using the mobile platform handler instead of SocketsHttpHandler.

Assert.Collection() Failure
Collection: [http.client.active_requests=1 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET], http.client.active_requests=-1 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET], http.client.request.duration=0.0143246 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET, http.response.status_code=200, network.protocol.version=1.1]]
Expected item count: 11
Actual item count:   3
   at System.Net.Http.Functional.Tests.HttpMetricsTest.<>c__DisplayClass19_0.<<AllSocketsHttpHandlerCounters_Success_Recorded>b__0>d.MoveNext() in /_/src/libraries/System.Net.Http/tests/FunctionalTests/MetricsTest.cs:line 618
--- End of stack trace from previous location ---
   at System.Threading.Tasks.TaskTimeoutExtensions.GetRealException(Task task) in /_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs:line 120
--- End of stack trace from previous location ---
   at System.Threading.Tasks.TaskTimeoutExtensions.WhenAllOrAnyFailed(Task[] tasks) in /_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs:line 90
   at System.Net.Test.Common.LoopbackServerFactory.<>c__DisplayClass6_0.<<CreateClientAndServerAsync>b__0>d.MoveNext() in /_/src/libraries/Common/tests/System/Net/Http/GenericLoopbackServer.cs:line 44
--- End of stack trace from previous location ---
   at System.Net.Test.Common.LoopbackServer.CreateServerAsync(Func`2 funcAsync, Options options) in /_/src/libraries/Common/tests/System/Net/Http/LoopbackServer.cs:line 107
   at System.Net.Http.Functional.Tests.HttpMetricsTest.AllSocketsHttpHandlerCounters_Success_Recorded() in /_/src/libraries/System.Net.Http/tests/FunctionalTests/MetricsTest.cs:line 575

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Issue Details

---

Saw failures like these in a few runtime-extra-platforms runs.
My guess is the test ended up using the mobile platform handler instead of SocketsHttpHandler.

Assert.Collection() Failure
Collection: [http.client.active_requests=1 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET], http.client.active_requests=-1 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET], http.client.request.duration=0.0143246 [url.scheme=http, server.address=127.0.0.1, server.port=42873, http.request.method=GET, http.response.status_code=200, network.protocol.version=1.1]]
Expected item count: 11
Actual item count:   3
   at System.Net.Http.Functional.Tests.HttpMetricsTest.<>c__DisplayClass19_0.<<AllSocketsHttpHandlerCounters_Success_Recorded>b__0>d.MoveNext() in /_/src/libraries/System.Net.Http/tests/FunctionalTests/MetricsTest.cs:line 618
--- End of stack trace from previous location ---
   at System.Threading.Tasks.TaskTimeoutExtensions.GetRealException(Task task) in /_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs:line 120
--- End of stack trace from previous location ---
   at System.Threading.Tasks.TaskTimeoutExtensions.WhenAllOrAnyFailed(Task[] tasks) in /_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs:line 90
   at System.Net.Test.Common.LoopbackServerFactory.<>c__DisplayClass6_0.<<CreateClientAndServerAsync>b__0>d.MoveNext() in /_/src/libraries/Common/tests/System/Net/Http/GenericLoopbackServer.cs:line 44
--- End of stack trace from previous location ---
   at System.Net.Test.Common.LoopbackServer.CreateServerAsync(Func`2 funcAsync, Options options) in /_/src/libraries/Common/tests/System/Net/Http/LoopbackServer.cs:line 107
   at System.Net.Http.Functional.Tests.HttpMetricsTest.AllSocketsHttpHandlerCounters_Success_Recorded() in /_/src/libraries/System.Net.Http/tests/FunctionalTests/MetricsTest.cs:line 575

Author:	MihaZupan
Assignees:	MihaZupan
Labels:	area-System.Net.Http
Milestone:	-

[MihaZupan]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[MihaZupan]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[simonrozsival]

@MihaZupan I think the problem must be somewhere else. The native mobile handler is located in the xamarin-android repo and AFAIK we can only use the HttpClientHandler on top of SocketsHttpHandler in runtime tests.

[MihaZupan]

Thanks @simonrozsival, you're right, it was using the correct handler.
The actual issue was that we weren't flowing down the meter factory correctly - I opened #90298.