Rename init_boot properties to ro.init_boot.*

Right now they're named ro.bootimage.* which is really confusing.
Change it so that if generic ramdisk is in boot.img, then name the
properties as ro.bootimage.*, otherwise if generic ramdisk is in
init_boot.img, then name the prop as ro.init_boot.*.

Bug: 211823573
Test: m dist
Change-Id: Icff3c7be04b9a3c6490fbf49ba4f05565b029890
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 9feb8af..1c29273 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -498,9 +498,9 @@
   def GetPartitionBuildProp(self, prop, partition):
     """Returns the inquired build property for the provided partition."""
 
-    # Boot image and init_boot image uses ro.[product.]bootimage instead of boot.
+    # Boot image uses ro.[product.]bootimage instead of boot.
     # This comes from the generic ramdisk
-    prop_partition = "bootimage" if partition == "boot" or partition == "init_boot" else partition
+    prop_partition = "bootimage" if partition == "boot" else partition
 
     # If provided a partition for this property, only look within that
     # partition's build.prop.