Remove length check to allow empty HDR10+ blobs to HWC

Bug: 212496177
Test: builds
Change-Id: Iad121cd6515e826c4b57976b14e7a5eb947b1728
diff --git a/graphics/composer/2.3/utils/hal/include/composer-hal/2.3/ComposerCommandEngine.h b/graphics/composer/2.3/utils/hal/include/composer-hal/2.3/ComposerCommandEngine.h
index 02f6212..f1d61f8 100644
--- a/graphics/composer/2.3/utils/hal/include/composer-hal/2.3/ComposerCommandEngine.h
+++ b/graphics/composer/2.3/utils/hal/include/composer-hal/2.3/ComposerCommandEngine.h
@@ -73,9 +73,7 @@
     }
 
     bool executeSetLayerPerFrameMetadataBlobs(uint16_t length) {
-        // must have at least one metadata blob
-        // of at least size 1 in queue (i.e {/*numBlobs=*/1, key, size, blob})
-        if (length < 4) {
+        if (length == 0) {
             return false;
         }