Reduce enabled keywords

For a basic E2E test, just enabling GC is sufficient.

Locally running this test, occasionally the test failed
because it didn't have the expected events. It's not
clear why, but with a brief tracee timeout of 1s,
collecting dotnet-trace's default keywords and enabling
all associated events is overkill for a fast E2E test.

Author: mdh1418

src/tests/tracing/eventpipe/userevents/dotnet-common.script

@@ -1,2 +1,2 @@
 let Microsoft_Windows_DotNETRuntime_flags = new_dotnet_provider_flags();
-record_dotnet_provider("Microsoft-Windows-DotNETRuntime", 0x100003801D, 4, Microsoft_Windows_DotNETRuntime_flags);
+record_dotnet_provider("Microsoft-Windows-DotNETRuntime", 0x1, 4, Microsoft_Windows_DotNETRuntime_flags);