Force HALs to explicitly enable legacy method for clearing buffer caches

Some HAL implementations can't support setLayerBuffer multiple times to
clear the per-layer buffer caches. Therefore, default this behavior to
disabled, and allow HALs to explcitily enable this behavior to obtain
the necessary memory savings.

Test: play videos with both true and false on both HIDL and AIDL
Bug: 285561686
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f70d9c4528888134e16003470b76dd1e81b8631d)
Merged-In: I928cef25e35cfc5337db4ceb8581bf5926b4fbe3
Change-Id: I928cef25e35cfc5337db4ceb8581bf5926b4fbe3
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index bcbe21a..689f51a 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -470,4 +470,18 @@
     scope: Public
     access: Readonly
     prop_name: "ro.surface_flinger.ignore_hdr_camera_layers"
-}
\ No newline at end of file
+}
+
+# When enabled, SurfaceFlinger will attempt to clear the per-layer HAL buffer cache slots for
+# buffers when they are evicted from the app cache by using additional setLayerBuffer commands.
+# Ideally, this behavior would always be enabled to reduce graphics memory consumption. However,
+# Some HAL implementations may not support the additional setLayerBuffer commands used to clear
+# the cache slots.
+prop {
+    api_name: "clear_slots_with_set_layer_buffer"
+    type: Boolean
+    scope: Public
+    access: Readonly
+    prop_name: "ro.surface_flinger.clear_slots_with_set_layer_buffer"
+}
+
diff --git a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
index 348a462..9660ff3 100644
--- a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
+++ b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
@@ -1,6 +1,10 @@
 props {
   module: "android.sysprop.SurfaceFlingerProperties"
   prop {
+    api_name: "clear_slots_with_set_layer_buffer"
+    prop_name: "ro.surface_flinger.clear_slots_with_set_layer_buffer"
+  }
+  prop {
     api_name: "color_space_agnostic_dataspace"
     type: Long
     prop_name: "ro.surface_flinger.color_space_agnostic_dataspace"