Populate os.version resource attribute (open-telemetry#16311)

Author: Arpan200502

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

@@ -20,6 +20,7 @@ public final class OsResource {
   private static final AttributeKey<String> OS_DESCRIPTION =
       AttributeKey.stringKey("os.description");
   private static final AttributeKey<String> OS_TYPE = AttributeKey.stringKey("os.type");
+  private static final AttributeKey<String> OS_VERSION = AttributeKey.stringKey("os.version");
 
   private static final Resource INSTANCE = buildResource();
 
@@ -59,6 +60,9 @@ static Resource buildResource() {
     } catch (SecurityException e) {
       // Ignore
     }
+    if (version != null) {
+      attributes.put(OS_VERSION, version);
+    }
     String osDescription = version != null ? os + ' ' + version : os;
     attributes.put(OS_DESCRIPTION, osDescription);
 

instrumentation/resources/library/src/test/java/io/opentelemetry/instrumentation/resources/OsResourceTest.java

@@ -7,6 +7,7 @@
 
 import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OS_DESCRIPTION;
 import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OS_TYPE;
+import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OS_VERSION;
 import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OsTypeIncubatingValues.AIX;
 import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OsTypeIncubatingValues.DARWIN;
 import static io.opentelemetry.semconv.incubating.OsIncubatingAttributes.OsTypeIncubatingValues.DRAGONFLYBSD;
@@ -29,11 +30,13 @@ class OsResourceTest {
 
   @Test
   @SetSystemProperty(key = "os.name", value = "Linux 4.11")
+  @SetSystemProperty(key = "os.version", value = "5.10")
   void linux() {
     Resource resource = OsResource.buildResource();
     assertThat(resource.getSchemaUrl()).isEqualTo(SchemaUrls.V1_24_0);
     assertThat(resource.getAttribute(OS_TYPE)).isEqualTo(LINUX);
     assertThat(resource.getAttribute(OS_DESCRIPTION)).isNotEmpty();
+    assertThat(resource.getAttribute(OS_VERSION)).isEqualTo("5.10");
   }
 
   @Test