Add bootanim property context, ro.bootanim.quiescent.enabled property

Add property & property context to configure whether the bootanimation
should be played in a quiescent boot.

Bug: 185118020
Test: Set property through PRODUCT_PRODUCT_PROPERTIES
Test: Read property from bootanimation process
Change-Id: Ib9e88444da7f5e8000d7367199f5230f1e4d26d9
diff --git a/private/bootanim.te b/private/bootanim.te
index 41c9179..cc6e0db 100644
--- a/private/bootanim.te
+++ b/private/bootanim.te
@@ -10,3 +10,5 @@
 
 # Read ro.boot.bootreason b/30654343
 get_prop(bootanim, bootloader_boot_reason_prop)
+
+get_prop(bootanim, bootanim_config_prop)
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