Add ramdisk image.

It is similar to recovery image.
Test: m nothing -j

Change-Id: I11389777c6bfb0c0d73bbb4c70091c1e70f44077
diff --git a/android/module.go b/android/module.go
index 05115d6..2662e2a 100644
--- a/android/module.go
+++ b/android/module.go
@@ -167,6 +167,7 @@
 	InstallInData() bool
 	InstallInTestcases() bool
 	InstallInSanitizerDir() bool
+	InstallInRamdisk() bool
 	InstallInRecovery() bool
 	InstallInRoot() bool
 	InstallBypassMake() bool
@@ -207,6 +208,7 @@
 	InstallInData() bool
 	InstallInTestcases() bool
 	InstallInSanitizerDir() bool
+	InstallInRamdisk() bool
 	InstallInRecovery() bool
 	InstallInRoot() bool
 	InstallBypassMake() bool
@@ -384,6 +386,9 @@
 	// Whether this module is installed to recovery partition
 	Recovery *bool
 
+	// Whether this module is installed to ramdisk
+	Ramdisk *bool
+
 	// Whether this module is built for non-native architecures (also known as native bridge binary)
 	Native_bridge_supported *bool `android:"arch_variant"`
 
@@ -867,6 +872,10 @@
 	return false
 }
 
+func (m *ModuleBase) InstallInRamdisk() bool {
+	return Bool(m.commonProperties.Ramdisk)
+}
+
 func (m *ModuleBase) InstallInRecovery() bool {
 	return Bool(m.commonProperties.Recovery)
 }
@@ -898,6 +907,10 @@
 	}
 }
 
+func (m *ModuleBase) InRamdisk() bool {
+	return m.base().commonProperties.ImageVariation == RamdiskVariation
+}
+
 func (m *ModuleBase) InRecovery() bool {
 	return m.base().commonProperties.ImageVariation == RecoveryVariation
 }
@@ -1649,6 +1662,10 @@
 	return m.module.InstallInSanitizerDir()
 }
 
+func (m *moduleContext) InstallInRamdisk() bool {
+	return m.module.InstallInRamdisk()
+}
+
 func (m *moduleContext) InstallInRecovery() bool {
 	return m.module.InstallInRecovery()
 }