Re-land removing RECOVERY_AS_BOOT check for init_first_stage

This has kept adb_debug.prop from being installed for
legacy devices with BOARD_USES_RECOVERY_AS_BOOT set to
true.

Bug: 192432810
Bug: 193291885
Test: `lunch aosp_flame-userdebug` and checks `get_build_var
      BOARD_USES_RECOVERY_AS_BOOT` is true.
Test: `make bootimage_debug` then checks
      $OUT/debug_ramdisk/adb_debug.prop exists
Test: build/soong/build_test.bash --dist --incremental

Change-Id: I28e2c082512791407167b610843f18731ed6d673
diff --git a/init/Android.bp b/init/Android.bp
index 3e8d4e3..46fa1f6 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", "BOARD_USES_RECOVERY_AS_BOOT"],
+    bool_variables: ["BOARD_BUILD_SYSTEM_ROOT_IMAGE"],
     properties: ["installable"],
 }
 
@@ -269,9 +269,6 @@
         BOARD_BUILD_SYSTEM_ROOT_IMAGE: {
             installable: false,
         },
-        BOARD_USES_RECOVERY_AS_BOOT: {
-            installable: false,
-        },
     },
 }