Move Jetifier Gradle projects into Support Library build

Bug: 72639070
Test: ./gradlew build
Test: ./gradlew projects | grep jetifier
Test: ./gradlew buildOnServer && \
      unzip -l ../../out/dist/top-of-tree-m2repository-0.zip \
      | grep -i jetifier

Change-Id: I3f91faf2a810b6badc9468e058d6f8df7ce2ea8c

diff --git a/settings.gradle b/settings.gradle
index dd6fd6a3..a5704cc 100644
--- a/settings.gradle
+++ b/settings.gradle

@@ -76,6 +76,10 @@
 includeProject(":slices-builders", "slices/builders")
 includeProject(":textclassifier", "textclassifier")
 includeProject(":webkit-codegen", "webkit-codegen")
+includeProject(":jetifier-core", "jetifier/jetifier/core")
+includeProject(":jetifier-gradle-plugin", "jetifier/jetifier/gradle-plugin")
+includeProject(":jetifier-standalone", "jetifier/jetifier/standalone")
+includeProject(":jetifier-preprocessor", "jetifier/jetifier/preprocessor")
 
 /////////////////////////////
 //