apex: add llndk libs as requireNativeLibs

"use_vendor: true" APEX modules may bundle vendor variants of cc
modules, which can depend on llndk stubs.

In that case, those llndk libraries should be also counted as required
libraries. (stored in 'requireNativeLibs' key in apex_manifest.json)

Bug: 138695532
Test: m nothing (runs soong tests)
Change-Id: If7ad4dec0e723c8d0c73ca60453b555063e14694
diff --git a/apex/apex.go b/apex/apex.go
index 574604b..fdb1cfc 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -932,7 +932,7 @@
 			}
 		} else {
 			// indirect dependencies
-			if am, ok := child.(android.ApexModule); ok && am.CanHaveApexVariants() && am.IsInstallableToApex() {
+			if am, ok := child.(android.ApexModule); ok {
 				// We cannot use a switch statement on `depTag` here as the checked
 				// tags used below are private (e.g. `cc.sharedDepTag`).
 				if cc.IsSharedDepTag(depTag) || cc.IsRuntimeDepTag(depTag) {
@@ -972,7 +972,7 @@
 						filesInfo = append(filesInfo, apexFile{fileToCopy, moduleName, dirInApex, nativeTest, cc, nil})
 						return true
 					}
-				} else {
+				} else if am.CanHaveApexVariants() && am.IsInstallableToApex() {
 					ctx.ModuleErrorf("unexpected tag %q for indirect dependency %q", depTag, depName)
 				}
 			}