Add a rule about platform_apis

As sdk_check.mk checks, soong starts to check every app.
If sdk_version is empty, platform_apis must be true.
If sdk_version is not empty, platform_apis must be false.

Test: soong test
Test: m
Bug: 132780927
Change-Id: I7ba702d616404d155f8ac40cd008828663ad1488
diff --git a/java/dexpreopt_test.go b/java/dexpreopt_test.go
index 22b7bb9..5550a4c 100644
--- a/java/dexpreopt_test.go
+++ b/java/dexpreopt_test.go
@@ -30,6 +30,7 @@
 				android_app {
 					name: "foo",
 					srcs: ["a.java"],
+					sdk_version: "current",
 				}`,
 			enabled: true,
 		},
@@ -57,6 +58,7 @@
 			bp: `
 				android_app {
 					name: "foo",
+					sdk_version: "current",
 				}`,
 			enabled: false,
 		},
@@ -66,11 +68,13 @@
 				android_app {
 					name: "foo",
 					static_libs: ["lib"],
+					sdk_version: "current",
 				}
 
 				java_library {
 					name: "lib",
 					srcs: ["a.java"],
+					sdk_version: "current",
 				}`,
 			enabled: true,
 		},