Revert Guava 20 features until we get the build working properly

*** Original change description ***

Remove deprecated methods with Guava 20 release

***

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=137945126

java/google/registry/request/Router.java

@@ -97,7 +97,7 @@ final class Router {
         } catch (InvocationTargetException e) {
           // This means an exception was thrown during the injection process while instantiating
           // the @Action class; we should propagate that underlying exception.
-          Throwables.throwIfUnchecked(e.getCause());
+          Throwables.propagateIfPossible(e.getCause());
           throw new AssertionError(
               "Component's @Action factory method somehow threw checked exception", e);
         }