Add rule emissions for appComponentFactory

This attribute was added in API 28 and is reflectively instantiated from a zero-argument constructor.

Test: make aapt2_tests
Change-Id: Ie9de0764165c6fe6c6fcda6cc38b0cc633f03bbd
diff --git a/tools/aapt2/java/ProguardRules.cpp b/tools/aapt2/java/ProguardRules.cpp
index d03cdb3..92487f4 100644
--- a/tools/aapt2/java/ProguardRules.cpp
+++ b/tools/aapt2/java/ProguardRules.cpp
@@ -259,6 +259,13 @@
             AddClass(node->line_number, result.value());
           }
         }
+        attr = node->FindAttribute(xml::kSchemaAndroid, "appComponentFactory");
+        if (attr) {
+          Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
+          if (result) {
+            AddClass(node->line_number, result.value());
+          }
+        }
         if (main_dex_only_) {
           xml::Attribute* default_process = node->FindAttribute(xml::kSchemaAndroid, "process");
           if (default_process) {