Group Timeline.getPeriod overloads

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=183238240

library/core/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -710,18 +710,6 @@ public abstract class Timeline {
         == C.INDEX_UNSET;
   }
 
-  /**
-   * Populates a {@link Period} with data for the period at the specified index. Does not populate
-   * {@link Period#id} and {@link Period#uid}.
-   *
-   * @param periodIndex The index of the period.
-   * @param period The {@link Period} to populate. Must not be null.
-   * @return The populated {@link Period}, for convenience.
-   */
-  public final Period getPeriod(int periodIndex, Period period) {
-    return getPeriod(periodIndex, period, false);
-  }
-
   /**
    * Calls {@link #getPeriodPosition(Window, Period, int, long, long)} with a zero default position
    * projection.
@@ -766,6 +754,18 @@ public abstract class Timeline {
     return Pair.create(periodIndex, periodPositionUs);
   }
 
+  /**
+   * Populates a {@link Period} with data for the period at the specified index. Does not populate
+   * {@link Period#id} and {@link Period#uid}.
+   *
+   * @param periodIndex The index of the period.
+   * @param period The {@link Period} to populate. Must not be null.
+   * @return The populated {@link Period}, for convenience.
+   */
+  public final Period getPeriod(int periodIndex, Period period) {
+    return getPeriod(periodIndex, period, false);
+  }
+
   /**
    * Populates a {@link Period} with data for the period at the specified index.
    *