Infer merge configs if not provided.

Bug: 221858722
Test: Create a merged package using inferred configs.
Test: atest --host releasetools_test
Change-Id: I93d67ca0f00be3f0e0424ed0a1e44c39ca2f3094
diff --git a/tools/releasetools/merge/merge_meta.py b/tools/releasetools/merge/merge_meta.py
index 81f6729..580b3ce 100644
--- a/tools/releasetools/merge/merge_meta.py
+++ b/tools/releasetools/merge/merge_meta.py
@@ -142,7 +142,8 @@
 
   merged_dict = OPTIONS.vendor_misc_info
   for key in OPTIONS.framework_misc_info_keys:
-    merged_dict[key] = OPTIONS.framework_misc_info[key]
+    if key in OPTIONS.framework_misc_info:
+      merged_dict[key] = OPTIONS.framework_misc_info[key]
 
   # If AVB is enabled then ensure that we build vbmeta.img.
   # Partial builds with AVB enabled may set PRODUCT_BUILD_VBMETA_IMAGE=false to