Revert "Revert "Fix NDK library sysroot arrangement.""

This reverts commit 961cf1cf9c59d54dc5693ca156f3eb79caab1102.

Reason for revert: Fixed

Change-Id: I3c5c0b89c924753b62c1bc126d7e64975ef7f137
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index 2473ba2..a824361 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -528,17 +528,20 @@
 	return false
 }
 
-func (stub *stubDecorator) install(ctx ModuleContext, path android.Path) {
-	arch := ctx.Target().Arch.ArchType.Name
-	// arm64 isn't actually a multilib toolchain, so unlike the other LP64
-	// architectures it's just installed to lib.
-	libDir := "lib"
-	if ctx.toolchain().Is64Bit() && arch != "arm64" {
-		libDir = "lib64"
-	}
+// Returns the install path for unversioned NDK libraries (currently only static
+// libraries).
+func getUnversionedLibraryInstallPath(ctx ModuleContext) android.InstallPath {
+	return getNdkSysrootBase(ctx).Join(ctx, "usr/lib", config.NDKTriple(ctx.toolchain()))
+}
 
-	installDir := getNdkInstallBase(ctx).Join(ctx, fmt.Sprintf(
-		"platforms/android-%s/arch-%s/usr/%s", stub.apiLevel, arch, libDir))
+// Returns the install path for versioned NDK libraries. These are most often
+// stubs, but the same paths are used for CRT objects.
+func getVersionedLibraryInstallPath(ctx ModuleContext, apiLevel android.ApiLevel) android.InstallPath {
+	return getUnversionedLibraryInstallPath(ctx).Join(ctx, apiLevel.String())
+}
+
+func (stub *stubDecorator) install(ctx ModuleContext, path android.Path) {
+	installDir := getVersionedLibraryInstallPath(ctx, stub.apiLevel)
 	stub.installPath = ctx.InstallFile(installDir, path.Base(), path)
 }