Update Observability AI Assistant screenshots (#4531)

(cherry picked from commit 71f7b35)

# Conflicts:
#	docs/en/serverless/ai-assistant/ai-assistant.asciidoc
#	docs/en/serverless/images/ai-assistant-button.png
#	docs/en/serverless/images/ai-assistant-chat.png
#	docs/en/serverless/images/ai-assistant-logs-prompts.png
#	docs/en/serverless/images/ai-assistant-logs.png
#	docs/en/serverless/images/ai-assistant-overview.gif

docs/en/observability/observability-ai-assistant.asciidoc

@@ -7,7 +7,7 @@ The AI Assistant uses generative AI to provide:
 * *Chat* —  have conversations with the AI Assistant. Chat uses function calling to request, analyze, and visualize your data.
 
 [role="screenshot"]
-image::images/obs-assistant2.gif[Observability AI assistant preview]
+image::images/obs-assistant2.gif[Observability AI assistant preview, 60%]
 
 The AI Assistant integrates with your large language model (LLM) provider through our supported Elastic connectors:
 
@@ -207,7 +207,7 @@ Your feedback helps us improve the AI Assistant!
 [[obs-ai-chat]]
 === Chat with the assistant
 
-Select the *AI Assistant* icon (image:images/icons/ai-assistant.svg[AI Assistant icon]) at the upper-right corner of any {observability} application to start the chat:
+Select the *AI Assistant* icon (image:images/ai-assistant-icon.png[AI Assistant icon]) at the upper-right corner of any {observability} application to start the chat.
 
 This opens the AI Assistant flyout, where you can ask the assistant questions about your instance:
 
@@ -264,12 +264,12 @@ AI Assistant contextual prompts throughout {observability} provide the following
 For example, in the log details, you'll see prompts for *What's this message?* and *How do I find similar log messages?*:
 
 [role="screenshot"]
-image::images/obs-ai-logs-prompts.png[]
+image::images/obs-ai-logs-prompts.png[Observability AI assistant logs prompts, 60%]
 
 Clicking a prompt generates a message specific to that log entry:
 
 [role="screenshot"]
-image::images/obs-ai-logs.gif[Observability AI assistant example, 75%]
+image::images/obs-ai-logs.gif[Observability AI assistant example, 60%]
 
 Continue a conversation from a contextual prompt by clicking *Start chat* to open the AI Assistant chat.
 
@@ -339,7 +339,7 @@ You can access the AI Assistant Settings page:
 The AI Assistant Settings page contains the following tabs:
 
 * *Settings*: Configures the main AI Assistant settings, which are explained directly within the interface.
-* *Knowledge base*: Manages <<obs-ai-kb-ui,knowledge base entries>>. 
+* *Knowledge base*: Manages <<obs-ai-kb-ui,knowledge base entries>>.
 * *Search Connectors*: Provides a link to {kib} *Search* -> *Content* -> *Connectors* UI for connectors configuration.
 [discrete]
 [[obs-ai-known-issues]]