Insert batch lock button after the duplicate button

Before it was placed after the read/unread toggle button, but this
caused a minor bug.

Fixes: #51
Change-Id: Ibe9ed8db3a90b1a9f8519a32773f9d4e243c2ed4
diff --git a/src/injections/batchlock_inject.css b/src/injections/batchlock_inject.css
new file mode 100644
index 0000000..da50618
--- /dev/null
+++ b/src/injections/batchlock_inject.css
@@ -0,0 +1,3 @@
+material-button[debugid="batchlock"] {
+  padding-left: 0;
+}