Revert "Do not set ro.iorapd.enable=true"

This reverts commit 4a4a4df0afa2bc94bf234905bd3810705e4916c3.

Reason for revert: This CL leaves the flag unset. Iorap is disabled by default now and rely on this flag to wake up in Rasta experiment.

IORap is disabled by default. We set this flag to run
Rasta experiment. This conflicts with go/aog/1557011.

To be more specific about how "ro.iorapd.enable" works now,
we added two device configs.
Iorap by default is off and starts when
(https://source.corp.google.com/android/system/iorap/iorapd.rc?q=iorapd.rc)

* ro.iorapd.enable is true excluding unset
* One of the device configs is true.

We have to set "ro.iorapd.enable" to true, so that iorap
can be started in the Rasta experiments.

Change-Id: I9630712b74cd411a5678632fb1ff695a84ed1048
diff --git a/target/product/runtime_libart.mk b/target/product/runtime_libart.mk
index 4da8794..e655d51 100644
--- a/target/product/runtime_libart.mk
+++ b/target/product/runtime_libart.mk
@@ -94,3 +94,15 @@
 PRODUCT_SYSTEM_PROPERTIES += \
     dalvik.vm.minidebuginfo=true \
     dalvik.vm.dex2oat-minidebuginfo=true
+
+# Two other device configs are added to IORap besides "ro.iorapd.enable".
+# IORap by default is off and starts when
+# (https://source.corp.google.com/android/system/iorap/iorapd.rc?q=iorapd.rc)
+#
+# * "ro.iorapd.enable" is true excluding unset
+# * One of the device configs is true.
+#
+# "ro.iorapd.enable" has to be set to true, so that iorap can be started.
+PRODUCT_SYSTEM_PROPERTIES += \
+    ro.iorapd.enable?=true
+