Move Function out of arch:common

Test: refactoring.
bug: 65115676
Change-Id: Ib05f0db0eb0edfa2ce8fa99a2227268e28cda052
diff --git a/app-toolkit/common/src/main/java/android/arch/core/util/Function.java b/app-toolkit/runtime/src/main/java/android/arch/core/util/Function.java
similarity index 100%
rename from app-toolkit/common/src/main/java/android/arch/core/util/Function.java
rename to app-toolkit/runtime/src/main/java/android/arch/core/util/Function.java