Adds jetifier plugin dependency into supportLib.

Test: N/A
Bug: b/64833662
Change-Id: I767101d9f72314827a581582a11194c7f3e49599
diff --git a/build.gradle b/build.gradle
index ec83da5..560bbda 100644
--- a/build.gradle
+++ b/build.gradle
@@ -25,6 +25,7 @@
     dependencies {
         classpath build_libs.gradle
         classpath build_libs.jacoco
+        classpath build_libs.jetifier
     }
 }