Don't list dynamic if a slot doesn't support DAP

If a slot doesn't support dynamic partitions, it's impossible to list
dynamic partitions on that slot. And we should just fall back to the
regular A/B in this case.

Bug: 180025432
Test: apply a retrofit package
Change-Id: I16c457b591e8c1d0cf1077a7be50dd9d8f61b8eb
diff --git a/common/dynamic_partition_control_stub.cc b/common/dynamic_partition_control_stub.cc
index b6eff84..7d0ef18 100644
--- a/common/dynamic_partition_control_stub.cc
+++ b/common/dynamic_partition_control_stub.cc
@@ -73,7 +73,9 @@
 }
 
 bool DynamicPartitionControlStub::ListDynamicPartitionsForSlot(
-    uint32_t current_slot, std::vector<std::string>* partitions) {
+    uint32_t slot,
+    uint32_t current_slot,
+    std::vector<std::string>* partitions) {
   return true;
 }