Cherry-picked from e6b969f3b in master. Do not merge.

Add boot property enabling ADBD over QEMU

Emulator and system image now support ADBD communication over QEMUD pipe rather
than over a TCP port forwarding. However, emulator has to know ahead of time
(before system starts booting) whether or not the system image supports ADBD
over pipe to properly setup the communication. For that, we introduce a boot
property "ro.adb.qemu" that is readable by the emulator early enough for the
proper ADB communication setup.

Change-Id: I978489c5acf46177b520e775d745bcc78f469837
diff --git a/target/board/generic/device.mk b/target/board/generic/device.mk
index 8b187d5..4edcc19 100644
--- a/target/board/generic/device.mk
+++ b/target/board/generic/device.mk
@@ -19,7 +19,8 @@
 
 PRODUCT_PROPERTY_OVERRIDES := \
     ro.ril.hsxpa=1 \
-    ro.ril.gprsclass=10
+    ro.ril.gprsclass=10 \
+    ro.adb.qemud=1
 
 PRODUCT_COPY_FILES := \
     development/data/etc/apns-conf.xml:system/etc/apns-conf.xml \
diff --git a/target/board/generic_x86/device.mk b/target/board/generic_x86/device.mk
index 1055cba..0dd2bc0 100644
--- a/target/board/generic_x86/device.mk
+++ b/target/board/generic_x86/device.mk
@@ -19,7 +19,8 @@
 
 PRODUCT_PROPERTY_OVERRIDES := \
     ro.ril.hsxpa=1 \
-    ro.ril.gprsclass=10
+    ro.ril.gprsclass=10 \
+    ro.adb.qemud=1
 
 PRODUCT_COPY_FILES := \
     development/data/etc/apns-conf.xml:system/etc/apns-conf.xml \
diff --git a/target/board/vbox_x86/device.mk b/target/board/vbox_x86/device.mk
index a76d8fa..66a6e84 100644
--- a/target/board/vbox_x86/device.mk
+++ b/target/board/vbox_x86/device.mk
@@ -21,7 +21,8 @@
 
 PRODUCT_PROPERTY_OVERRIDES := \
     ro.ril.hsxpa=1 \
-    ro.ril.gprsclass=10
+    ro.ril.gprsclass=10 \
+    ro.adb.qemud=1
 
 LOCAL_KERNEL := prebuilt/android-x86/kernel/kernel-vbox