apex: Deprecate legacy_android10_support prop

min_sdk_version = 29 implies that the module should support Android10.

Bug: 150431944
Test: m
Change-Id: Iad90a239898f59456900ae7816b90379b1b43406
diff --git a/apex/apex_test.go b/apex/apex_test.go
index ad91878..b8e8878 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3737,7 +3737,7 @@
 			name: "myapex",
 			key: "myapex.key",
 			native_shared_libs: ["mylib"],
-			legacy_android10_support: true,
+			min_sdk_version: "29",
 		}
 
 		apex_key {