pw_blob_store: Allow large deferred write buffers

Remove size restrictions on the internal buffer. These are no longer
needed since the addition of the flash_write_size_bytes parameter.

Remove flash_write_size_bytes argument default for BlobStoreBuffer

Change-Id: If47655ae19efc46942894e7b0f4727c84936849e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/25100
Commit-Queue: David Rogers <davidrogers@google.com>
Reviewed-by: Ewout van Bekkum <ewout@google.com>
diff --git a/pw_blob_store/blob_store_chunk_write_test.cc b/pw_blob_store/blob_store_chunk_write_test.cc
index cf7219d..49e0016 100644
--- a/pw_blob_store/blob_store_chunk_write_test.cc
+++ b/pw_blob_store/blob_store_chunk_write_test.cc
@@ -59,7 +59,7 @@
     snprintf(name, sizeof(name), "Blob%u", static_cast<unsigned>(chunk_size));
 
     BlobStoreBuffer<kBufferSize> blob(
-        name, partition_, &checksum, kvs::TestKvs());
+        name, partition_, &checksum, kvs::TestKvs(), kBufferSize);
     EXPECT_EQ(Status::Ok(), blob.Init());
 
     BlobStore::BlobWriter writer(blob);