Remove AppContext switch

This isn't necessary. The existing OpenTelemetry ActivitySource uses the assembly name of SqlTelemetryHelper, but this type isn't in the SqlClient assembly. We can thus use an ActivitySource name of Microsoft.Data.SqlClient without generating any conflicts.

Author: edwardneal

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs

@@ -94,13 +94,6 @@ internal static class LocalAppContextSwitches
     private const string SuppressInsecureTlsWarningString =
         "Switch.Microsoft.Data.SqlClient.SuppressInsecureTLSWarning";
 
-    /// <summary>
-    /// The name of the app context switch that controls whether to suppress
-    /// the creation of <see cref="System.Diagnostics.Activity"/> instances.
-    /// </summary>
-    private const string SuppressNativeActivityTelemetryString =
-        "Switch.Microsoft.Data.SqlClient.SuppressNativeActivityTelemetry";
-
     /// <summary>
     /// The name of the app context switch that controls whether TdsParser
     /// truncates (rather than rounds) decimal and SqlDecimal values when
@@ -220,11 +213,6 @@ private enum SwitchValue : byte
     /// </summary>
     private static SwitchValue s_suppressInsecureTlsWarning = SwitchValue.None;
 
-    /// <summary>
-    /// The cached value of the SuppressNativeActivityTelemetry switch.
-    /// </summary>
-    private static SwitchValue s_suppressNativeActivityTelemetry = SwitchValue.None;
-
     /// <summary>
     /// The cached value of the TruncateScaledDecimal switch.
     /// </summary>
@@ -499,17 +487,6 @@ public static bool GlobalizationInvariantMode
             defaultValue: false,
             ref s_suppressInsecureTlsWarning);
 
-    /// <summary>
-    /// Suppresses the creation of <see cref="System.Diagnostics.Activity"/> instances
-    /// within SqlClient. This prevents duplicate activities from being recorded if an
-    /// existing library already hooks other diagnostic pathways and creates them.
-    /// </summary>
-    public static bool SuppressNativeActivityTelemetry =>
-        AcquireAndReturn(
-            SuppressNativeActivityTelemetryString,
-            defaultValue: false,
-            ref s_suppressNativeActivityTelemetry);
-
     /// <summary>
     /// When set to true, TdsParser will truncate (rather than round) decimal
     /// and SqlDecimal values when scaling them.

src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/LocalAppContextSwitchesTest.cs

@@ -20,7 +20,6 @@ public void TestDefaultAppContextSwitchValues()
     {
         Assert.False(LocalAppContextSwitches.LegacyRowVersionNullBehavior);
         Assert.False(LocalAppContextSwitches.SuppressInsecureTlsWarning);
-        Assert.False(LocalAppContextSwitches.SuppressNativeActivityTelemetry);
         Assert.False(LocalAppContextSwitches.MakeReadAsyncBlocking);
         Assert.True(LocalAppContextSwitches.UseMinimumLoginTimeout);
         Assert.True(LocalAppContextSwitches.LegacyVarTimeZeroScaleBehaviour);