Fix android_test install path.

Test: m nothing + diff soong mk and ninja files.
Bug: 140795853
Change-Id: I3667eac951dea7e447cf73219ff89199fca9ed63
diff --git a/android/paths.go b/android/paths.go
index 0d64a61..8bd2c61 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -44,6 +44,7 @@
 	BaseModuleContext
 
 	InstallInData() bool
+	InstallInTestcases() bool
 	InstallInSanitizerDir() bool
 	InstallInRecovery() bool
 	InstallBypassMake() bool
@@ -1155,6 +1156,8 @@
 	var partition string
 	if ctx.InstallInData() {
 		partition = "data"
+	} else if ctx.InstallInTestcases() {
+		partition = "testcases"
 	} else if ctx.InstallInRecovery() {
 		// the layout of recovery partion is the same as that of system partition
 		partition = "recovery/root/system"