Update Javadoc "since" tags in log correlation libraries. (#1539)

0.17 is the first non-experimental release, and it has some breaking changes, so
so we should reset the "since" tags to 0.17.

Author: sebright2

contrib/log_correlation/log4j2/src/main/java/io/opencensus/contrib/logcorrelation/log4j2/OpenCensusTraceContextDataInjector.java

@@ -48,7 +48,7 @@
  *   <li><code>%X{traceSampled}</code>
  * </ul>
  *
- * @since 0.16
+ * @since 0.17
  * @see <a
  *     href="https://logging.apache.org/log4j/2.x/log4j-core/apidocs/org/apache/logging/log4j/core/ContextDataInjector.html">org.apache.logging.log4j.core.ContextDataInjector</a>
  */
@@ -57,28 +57,28 @@ public final class OpenCensusTraceContextDataInjector implements ContextDataInje
   /**
    * Context key for the current trace ID. The name is {@value}.
    *
-   * @since 0.16
+   * @since 0.17
    */
   public static final String TRACE_ID_CONTEXT_KEY = "traceId";
 
   /**
    * Context key for the current span ID. The name is {@value}.
    *
-   * @since 0.16
+   * @since 0.17
    */
   public static final String SPAN_ID_CONTEXT_KEY = "spanId";
 
   /**
    * Context key for the sampling decision of the current span. The name is {@value}.
    *
-   * @since 0.16
+   * @since 0.17
    */
   public static final String TRACE_SAMPLED_CONTEXT_KEY = "traceSampled";
 
   /**
    * Constructor to be called by Log4j.
    *
-   * @since 0.16
+   * @since 0.17
    */
   public OpenCensusTraceContextDataInjector() {}
 

contrib/log_correlation/stackdriver/src/main/java/io/opencensus/contrib/logcorrelation/stackdriver/OpenCensusTraceLoggingEnhancer.java

@@ -29,15 +29,15 @@
 /**
  * Stackdriver {@link LoggingEnhancer} that adds OpenCensus tracing data to log entries.
  *
- * @since 0.15
+ * @since 0.17
  */
 public final class OpenCensusTraceLoggingEnhancer implements LoggingEnhancer {
 
   /**
    * Name of the property that overrides the default project ID (overrides the value returned by
    * {@code com.google.cloud.ServiceOptions.getDefaultProjectId()}). The name is {@value}.
    *
-   * @since 0.15
+   * @since 0.17
    */
   public static final String PROJECT_ID_PROPERTY_NAME =
       "io.opencensus.contrib.logcorrelation.stackdriver.OpenCensusTraceLoggingEnhancer.projectId";
@@ -57,7 +57,7 @@ public final class OpenCensusTraceLoggingEnhancer implements LoggingEnhancer {
    * can be specified with a {@link java.util.logging} property or a system property, with
    * preference given to the logging property.
    *
-   * @since 0.15
+   * @since 0.17
    */
   public OpenCensusTraceLoggingEnhancer() {
     this(lookUpProjectId());