Enable HWASan for multiple modules in one place(Soong)

Environment variables HWASAN_INCLUDE_PATHS and
PRODUCT_HWASAN_INCLUDE_PATHS can be used to enable HWASan for multiple
modules, by just adding the module directory to the env variable.

Bug: b/271948407
Test: Set specific module directory to above env variable and check the
assembly codes of output elf files after building, finding hwasan
related symbols inside.

Change-Id: Ic49b515830c4469ca5fa94f547b26c0fb602fc54
diff --git a/android/variable.go b/android/variable.go
index 249d53b..0b3111b 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -306,6 +306,8 @@
 	MemtagHeapAsyncIncludePaths []string `json:",omitempty"`
 	MemtagHeapSyncIncludePaths  []string `json:",omitempty"`
 
+	HWASanIncludePaths []string `json:",omitempty"`
+
 	VendorPath    *string `json:",omitempty"`
 	OdmPath       *string `json:",omitempty"`
 	ProductPath   *string `json:",omitempty"`