COPY: secure media -> secure uploads (#24643)

Fixing up the last few holdouts

plugins/chat/spec/plugin_spec.rb

@@ -236,8 +236,8 @@ describe Chat do
     end
   end
 
-  describe "secure media compatibility" do
-    it "disables chat uploads if secure media changes from disabled to enabled" do
+  describe "secure uploads compatibility" do
+    it "disables chat uploads if secure uploads changes from disabled to enabled" do
       enable_secure_uploads
       expect(SiteSetting.chat_allow_uploads).to eq(false)
       last_history = UserHistory.last

plugins/chat/spec/validators/chat_allow_uploads_validator_spec.rb

@@ -6,7 +6,7 @@ RSpec.describe Chat::AllowUploadsValidator do
     expect(validator.valid_value?("f")).to eq(true)
   end
 
-  context "when secure media is enabled" do
+  context "when secure uploads is enabled" do
     before do
       SiteSetting.chat_allow_uploads = false
       enable_secure_uploads