Fix possible crash before dereference symbol

Bug: b/180625460
Flag: EXEMPT bugfix
Test: Verified affected tests passed.
Change-Id: I8465dc3062845fe79ee2f19b3cd5121d57afdb53
diff --git a/tools/aapt2/link/ManifestFixer.cpp b/tools/aapt2/link/ManifestFixer.cpp
index cbf2c2f..382b088 100644
--- a/tools/aapt2/link/ManifestFixer.cpp
+++ b/tools/aapt2/link/ManifestFixer.cpp
@@ -198,6 +198,7 @@
           android::DiagMessage(el->line_number)
           << "Cannot find symbol for android:configChanges with min sdk: "
           << context->GetMinSdkVersion());
+      return false;
     }
 
     std::stringstream new_value;