AAPT2: Emit @keep for sub-process app classes

Test: atest aapt2_tests
Bug: 197264681
Change-Id: I1f6cabfd0f3ce4c3c661d9dc132629d8c83048d9
diff --git a/tools/aapt2/java/ProguardRules.cpp b/tools/aapt2/java/ProguardRules.cpp
index b939f35..4a2d0ae 100644
--- a/tools/aapt2/java/ProguardRules.cpp
+++ b/tools/aapt2/java/ProguardRules.cpp
@@ -311,7 +311,7 @@
               component_process ? component_process->value : default_process_;
           get_name = !process.empty() && process[0] != ':';
         }
-      } else if (node->name == "instrumentation") {
+      } else if (node->name == "instrumentation" || node->name == "process") {
         get_name = true;
       }