Set __ANDROID_API__ for vendor modules to vndk version.

When building vendor modules with BOARD_VNDK_VERSION=current, the
API of the vendor modules will be current PLATFORM_VNDK_VERSION.
__ANDROID_API_FUTURE__ will be used as before if the version is a
CODENAME.

If BOARD_VNDK_VERSION is not "current", that means the VNDK version
of the vendor modules is BOARD_VNDK_VERSION.

Bug: 74833244
Test: Build and check boot.
Change-Id: I383c76a36101e39c70575b463880b52d3e9d90bb
diff --git a/cc/compiler.go b/cc/compiler.go
index b2095a6..ffb8342 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -308,8 +308,13 @@
 	}
 
 	if ctx.useVndk() {
+		// sdkVersion() returns VNDK version for vendor modules.
+		version := ctx.sdkVersion()
+		if version == "current" {
+			version = "__ANDROID_API_FUTURE__"
+		}
 		flags.GlobalFlags = append(flags.GlobalFlags,
-			"-D__ANDROID_API__=__ANDROID_API_FUTURE__", "-D__ANDROID_VNDK__")
+			"-D__ANDROID_API__="+version, "-D__ANDROID_VNDK__")
 	}
 
 	instructionSet := String(compiler.Properties.Instruction_set)