use constants for attribute references

Author: jaydeluca

instrumentation/resources/library/src/main/java/io/opentelemetry/instrumentation/resources/ProcessResource.java

@@ -23,13 +23,13 @@
 public final class ProcessResource {
 
   // copied from ProcessIncubatingAttributes
-  private static final AttributeKey<List<String>> PROCESS_COMMAND_ARGS =
+  static final AttributeKey<List<String>> PROCESS_COMMAND_ARGS =
       AttributeKey.stringArrayKey("process.command_args");
-  private static final AttributeKey<String> PROCESS_COMMAND_LINE =
+  static final AttributeKey<String> PROCESS_COMMAND_LINE =
       AttributeKey.stringKey("process.command_line");
-  private static final AttributeKey<String> PROCESS_EXECUTABLE_PATH =
+  static final AttributeKey<String> PROCESS_EXECUTABLE_PATH =
       AttributeKey.stringKey("process.executable.path");
-  private static final AttributeKey<Long> PROCESS_PID = AttributeKey.longKey("process.pid");
+  static final AttributeKey<Long> PROCESS_PID = AttributeKey.longKey("process.pid");
 
   // Note: This pattern doesn't support file paths with spaces in them.
   // Important: This is statically used in buildResource, so must be declared/initialized first.

instrumentation/resources/library/src/testSecurityManager/java/io/opentelemetry/instrumentation/resources/SecurityManagerResourceTest.java

@@ -7,7 +7,6 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.sdk.resources.Resource;
 import org.junit.jupiter.api.Test;
@@ -26,7 +25,7 @@ class SecurityManagerResourceTest {
   @Test
   void hostResourceTestEmpty() {
     Attributes attributes = HostResource.buildResource().getAttributes();
-    assertThat(attributes.asMap()).containsOnlyKeys(AttributeKey.stringKey("host.name"));
+    assertThat(attributes.asMap()).containsOnlyKeys(HostResource.HOST_NAME);
   }
 
   @Test
@@ -37,7 +36,7 @@ void osResourceEmpty() {
   @Test
   void processResourceEmpty() {
     Attributes attributes = ProcessResource.buildResource().getAttributes();
-    assertThat(attributes.asMap()).containsOnlyKeys(AttributeKey.longKey("process.pid"));
+    assertThat(attributes.asMap()).containsOnlyKeys(ProcessResource.PROCESS_PID);
   }
 
   @Test