Resolve a gmscore one version violation by removing an unused dep

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=169435879

Author: clm

google-http-client/src/main/java/com/google/api/client/util/Throwables.java

@@ -75,12 +75,7 @@ public static RuntimeException propagate(Throwable throwable) {
    */
   public static void propagateIfPossible(Throwable throwable) {
     if (throwable != null) {
-      if (throwable instanceof RuntimeException) {
-        throw (RuntimeException) throwable;
-      }
-      if (throwable instanceof Error) {
-        throw (Error) throwable;
-      }
+      com.google.common.base.Throwables.throwIfUnchecked(throwable);
     }
   }