[receiver/redis] Add bytes unit in metadata.yaml (open-telemetry#23454)

This PR adds the bytes unit to metrics where this is missing. unit is a
required field, see
https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/cmd/mdatagen/metadata-schema.yaml#L72-L73.

.chloggen/add-units-redisreceiver.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: redisreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Updates metric unit from no unit to Bytes.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23454]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  Affected metrics can be found below.
+  - redis.clients.max_input_buffer
+  - redis.clients.max_output_buffer
+  - redis.replication.backlog_first_byte_offset
+  - redis.replication.offset

receiver/redisreceiver/documentation.md

@@ -34,15 +34,15 @@ Biggest input buffer among current client connections
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-|  | Gauge | Int |
+| By | Gauge | Int |
 
 ### redis.clients.max_output_buffer
 
 Longest output list among current client connections
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-|  | Gauge | Int |
+| By | Gauge | Int |
 
 ### redis.commands
 
@@ -242,15 +242,15 @@ The master offset of the replication backlog buffer
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-|  | Gauge | Int |
+| By | Gauge | Int |
 
 ### redis.replication.offset
 
 The server's current replication offset
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-|  | Gauge | Int |
+| By | Gauge | Int |
 
 ### redis.slaves.connected
 

receiver/redisreceiver/metadata.yaml

@@ -112,14 +112,14 @@ metrics:
   redis.clients.max_input_buffer:
     enabled: true
     description: Biggest input buffer among current client connections
-    unit: ""
+    unit: "By"
     gauge:
       value_type: int
 
   redis.clients.max_output_buffer:
     enabled: true
     description: Longest output list among current client connections
-    unit: ""
+    unit: "By"
     gauge:
       value_type: int
 
@@ -284,14 +284,14 @@ metrics:
   redis.replication.backlog_first_byte_offset:
     enabled: true
     description: The master offset of the replication backlog buffer
-    unit: ""
+    unit: "By"
     gauge:
       value_type: int
 
   redis.replication.offset:
     enabled: true
     description: The server's current replication offset
-    unit: ""
+    unit: "By"
     gauge:
       value_type: int