AAPT2: Emit @keep for sub-process app classes

Test: atest aapt2_tests
Bug: 197264681
Change-Id: I1f6cabfd0f3ce4c3c661d9dc132629d8c83048d9
diff --git a/tools/aapt2/java/ProguardRules_test.cpp b/tools/aapt2/java/ProguardRules_test.cpp
index e104066..466b7d9 100644
--- a/tools/aapt2/java/ProguardRules_test.cpp
+++ b/tools/aapt2/java/ProguardRules_test.cpp
@@ -44,6 +44,9 @@
             android:name="com.foo.BarApplication"
             android:zygotePreloadName="com.foo.BarZygotePreload"
             >
+          <processes>
+            <process android:process=":sub" android:name="com.foo.BazApplication" />
+          </processes>
           <activity android:name="com.foo.BarActivity"/>
           <service android:name="com.foo.BarService"/>
           <receiver android:name="com.foo.BarReceiver"/>
@@ -59,6 +62,7 @@
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarAppComponentFactory { <init>(); }"));
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarBackupAgent { <init>(); }"));
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarApplication { <init>(); }"));
+  EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BazApplication { <init>(); }"));
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarActivity { <init>(); }"));
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarService { <init>(); }"));
   EXPECT_THAT(actual, HasSubstr("-keep class com.foo.BarReceiver { <init>(); }"));