Make relative path for native_bridge binaries configurable

This change introduces NativeBridgeRelativePath and
NativeBridgeSecondaryRelativePath product variables to
make relative path to native_bridge binaries configurable.

It also removes moves information about native bridge
host architecture to Target and sets it during decodeTargetProductVariables

Test: make PRODUCT-cf_x86_phone-userdebug dist
Change-Id: Ie736e81eae507e1775566ce9f29135011b12af27
diff --git a/android/variable.go b/android/variable.go
index fcd92d4..47586a7 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -165,15 +165,17 @@
 	DeviceSecondaryCpuVariant  *string  `json:",omitempty"`
 	DeviceSecondaryAbi         []string `json:",omitempty"`
 
-	NativeBridgeArch        *string  `json:",omitempty"`
-	NativeBridgeArchVariant *string  `json:",omitempty"`
-	NativeBridgeCpuVariant  *string  `json:",omitempty"`
-	NativeBridgeAbi         []string `json:",omitempty"`
+	NativeBridgeArch         *string  `json:",omitempty"`
+	NativeBridgeArchVariant  *string  `json:",omitempty"`
+	NativeBridgeCpuVariant   *string  `json:",omitempty"`
+	NativeBridgeAbi          []string `json:",omitempty"`
+	NativeBridgeRelativePath *string  `json:",omitempty"`
 
-	NativeBridgeSecondaryArch        *string  `json:",omitempty"`
-	NativeBridgeSecondaryArchVariant *string  `json:",omitempty"`
-	NativeBridgeSecondaryCpuVariant  *string  `json:",omitempty"`
-	NativeBridgeSecondaryAbi         []string `json:",omitempty"`
+	NativeBridgeSecondaryArch         *string  `json:",omitempty"`
+	NativeBridgeSecondaryArchVariant  *string  `json:",omitempty"`
+	NativeBridgeSecondaryCpuVariant   *string  `json:",omitempty"`
+	NativeBridgeSecondaryAbi          []string `json:",omitempty"`
+	NativeBridgeSecondaryRelativePath *string  `json:",omitempty"`
 
 	HostArch          *string `json:",omitempty"`
 	HostSecondaryArch *string `json:",omitempty"`