Return SDK attributes in default Resource. (#1528)

* Populate SDK resource by default.

* Add test

* Newline

* Revert "Newline"

This reverts commit e6ff4b4.

* Revert "Add test"

This reverts commit f2eaa7c.

Author: Anuraag Agrawal

sdk/src/main/java/io/opentelemetry/sdk/metrics/MeterSdkProvider.java

@@ -88,7 +88,7 @@ public static Builder builder() {
   public static final class Builder {
 
     private Clock clock = MillisClock.getInstance();
-    private Resource resource = Resource.getTelemetrySdk().merge(Resource.getDefault());
+    private Resource resource = Resource.getDefault();
 
     private Builder() {}
 

sdk/src/main/java/io/opentelemetry/sdk/resources/Resource.java

@@ -54,7 +54,11 @@ public abstract class Resource {
               .setAttribute("telemetry.sdk.version", readVersion())
               .build());
   private static final Resource DEFAULT =
-      new EnvAutodetectResource.Builder().readEnvironmentVariables().readSystemProperties().build();
+      new EnvAutodetectResource.Builder()
+          .readEnvironmentVariables()
+          .readSystemProperties()
+          .build()
+          .merge(TELEMETRY_SDK);
 
   @Nullable
   private static String readVersion() {

sdk/src/main/java/io/opentelemetry/sdk/trace/TracerSdkProvider.java

@@ -137,7 +137,7 @@ public static class Builder {
 
     private Clock clock = MillisClock.getInstance();
     private IdsGenerator idsGenerator = new RandomIdsGenerator();
-    private Resource resource = Resource.getTelemetrySdk().merge(Resource.getDefault());
+    private Resource resource = Resource.getDefault();
 
     /**
      * Assign a {@link Clock}.