Remove PathForOutput from InstallPathToOnDevicePath

The next patches will make more InstallPaths use the Make output
directory, which is not inside PathForOutput.  Fix the assumption
that the InstallPath is relative to PathForOutput by storing
enough information in the InstallPath to find the on-device path
without PathForOutput.

Bug: 204136549
Test: soong tests
Change-Id: Icb3eeef3f1c72f773f333267f8a7dfc503feacb5

android/paths.go

@@ -1571,6 +1571,8 @@ type InstallPath struct {
 	// For example, it is host/<os>-<arch> for host modules, and target/product/<device>/<partition> for device modules.
 	partitionDir string
 
+	partition string
+
 	// makePath indicates whether this path is for Soong (false) or Make (true).
 	makePath bool
 }
@@ -1716,6 +1718,7 @@ func pathForInstall(ctx PathContext, os OsType, arch ArchType, partition string,
 		basePath:     basePath{partionPath, ""},
 		soongOutDir:  ctx.Config().soongOutDir,
 		partitionDir: partionPath,
+		partition:    partition,
 		makePath:     false,
 	}
 
@@ -1741,8 +1744,7 @@ func PathForMainlineSdksInstall(ctx PathContext, paths ...string) InstallPath {
 }
 
 func InstallPathToOnDevicePath(ctx PathContext, path InstallPath) string {
-	rel := Rel(ctx, PathForOutput(ctx, "target", "product", ctx.Config().DeviceName()).String(), path.String())
-
+	rel := Rel(ctx, strings.TrimSuffix(path.PartitionDir(), path.partition), path.String())
 	return "/" + rel
 }