[journeys] Change page screeshots on steps (elastic#188332)

## Summary

We have seen some random browser crashes during screenshot taken on CI
and hopefully these changes will help to minimize it:

- no screenshots on step success by default: we don't use the artifact
at the moment, so we don't need screenshots for all steps
- catch errors on screenshot take and log error, but don't throw error;
it will be thrown for step failure explicitly

packages/kbn-journeys/journey/journey_config.ts

@@ -142,6 +142,11 @@ export interface JourneyConfigOptions<CtxExt extends { '@timestamp'?: number | u
    * },
    */
   synthtrace?: JourneySynthtrace<CtxExt>;
+
+  /**
+   * Take browser page screenshot on every step complete
+   */
+  takeScreenshotOnSuccess?: boolean;
 }
 
 export class JourneyConfig<CtxExt extends object> {
@@ -219,4 +224,8 @@ export class JourneyConfig<CtxExt extends object> {
   getSynthtraceConfig() {
     return this.#opts.synthtrace;
   }
+
+  takeScreenshotOnSuccess() {
+    return !!this.#opts.takeScreenshotOnSuccess;
+  }
 }

packages/kbn-journeys/journey/journey_ftr_harness.ts

@@ -305,17 +305,37 @@ export class JourneyFtrHarness {
     ]);
   }
 
+  private async takeScreenshots(page: Page) {
+    let screenshot;
+    let fs;
+    // screenshots taking might crash the browser
+    try {
+      screenshot = await page.screenshot({ animations: 'disabled' });
+      fs = await page.screenshot({ animations: 'disabled', fullPage: true });
+    } catch (e) {
+      if (!screenshot) {
+        this.log.error(`Failed to take screenshot of the visible viewport: ${e.message}`);
+      } else if (screenshot && !fs) {
+        this.log.error(`Failed to take screenshot of the full scrollable page: ${e.message}`);
+      } else {
+        this.log.error(`Unknown error on taking screenshots`);
+      }
+    }
+
+    return { screenshot, fs };
+  }
+
   private async onStepSuccess(step: AnyStep) {
     if (!this.page) {
       return;
     }
 
-    const [screenshot, fs] = await Promise.all([
-      this.page.screenshot(),
-      this.page.screenshot({ fullPage: true }),
-    ]);
-
-    await this.screenshots.addSuccess(step, screenshot, fs);
+    if (this.journeyConfig.takeScreenshotOnSuccess()) {
+      const { screenshot, fs } = await this.takeScreenshots(this.page);
+      if (screenshot && fs) {
+        await this.screenshots.addSuccess(step, screenshot, fs);
+      }
+    }
   }
 
   private async onStepError(step: AnyStep, err: Error) {
@@ -325,12 +345,10 @@ export class JourneyFtrHarness {
     }
 
     if (this.page) {
-      const [screenshot, fs] = await Promise.all([
-        this.page.screenshot(),
-        this.page.screenshot({ fullPage: true }),
-      ]);
-
-      await this.screenshots.addError(step, screenshot, fs);
+      const { screenshot, fs } = await this.takeScreenshots(this.page);
+      if (screenshot && fs) {
+        await this.screenshots.addError(step, screenshot, fs);
+      }
     }
   }