Revert "Re-land removing RECOVERY_AS_BOOT check for init_first_stage"

This reverts commit 4818f74888bfe528d7a2090d18478c95aa88c497.

The previous commit might introduce a build break on legacy
devices that with a smaller /boot partition size, because it
outputs the first-stage init and the second-stage init binaries
in the following locations, respectively (when
BOARD_USES_RECOVERY_AS_BOOT is true).

    * $OUT/recovery/root/first_stage_ramdisk/init
    * $OUT/recovery/root/system/bin/init

The first one is not needed because there is already a symlink
under $OUT/recovery/root:  init -> /system/bin/init.

Bug: 193565271
Test: `lunch aosp_flame-userdebug`, `make bootimage_debug` then
      checks the output under $OUT/debug_ramdisk/.
Test: Performs the same check for `lunch aosp_bramble-userdebug`.
Change-Id: I6277a6c4c0980bd976cc35db6ca99eafc6bf3f5a
diff --git a/init/Android.bp b/init/Android.bp
index 46fa1f6..3e8d4e3 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -257,7 +257,7 @@
     name: "init_first_stage_cc_defaults",
     module_type: "cc_defaults",
     config_namespace: "ANDROID",
-    bool_variables: ["BOARD_BUILD_SYSTEM_ROOT_IMAGE"],
+    bool_variables: ["BOARD_BUILD_SYSTEM_ROOT_IMAGE", "BOARD_USES_RECOVERY_AS_BOOT"],
     properties: ["installable"],
 }
 
@@ -269,6 +269,9 @@
         BOARD_BUILD_SYSTEM_ROOT_IMAGE: {
             installable: false,
         },
+        BOARD_USES_RECOVERY_AS_BOOT: {
+            installable: false,
+        },
     },
 }