Drop racy parallel pre-build step from inapp-e2e-tests workflow

After the SDK-170 migration of this workflow to ubuntu-latest + KVM
(#1048, commit 7d4a80b), every PR opened against master has been
failing the In-App Message E2E Tests check at the build stage:

    Execution failed for task ':integration-tests:mergeDebugAndroidTestResources'.
    > Cannot access output property 'blameLogOutputFolder' …
       > Failed to create MD5 hash for file
         '.../merged_res_blame_folder/.../values-az.json' as it does not exist.

with this warning a few lines earlier:

    Detected multiple Kotlin daemon sessions at kotlin/sessions

The 'Pre-download Gradle and Build (Parallel with Emulator)' step
backgrounded a separate Gradle invocation that was meant to assemble
the APKs while the emulator booted. On macos-15-intel the background
process was resource-starved during emulator boot (2 cores / slow HVF)
so it usually finished or stalled before the action's Gradle started.
On ubuntu-latest + KVM both Gradle processes get real CPU and run in
true parallel, racing on the same integration-tests/build/intermediates
directory.

Affected runs:
  - feature/sdk-338-mobile-inbox-customization: 5 failures
  - fix/SDK-412-UUA-Naming-inconsistencies: 1 failure
  - SDK-170-emulator-network-trace: green (warm cache made the race
    window negligible — masked the regression during review)

Removing the parallel pre-build is sufficient. The action's script
already invokes ':integration-tests:connectedDebugAndroidTest' which
transitively builds the APKs it needs. Expected wall-clock impact:
+30-90s on a cold Gradle cache, traded for 'all PRs can run this
check'.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: franco-zalamena-iterable

.github/workflows/inapp-e2e-tests.yml

@@ -70,16 +70,21 @@ jobs:
           key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
           restore-keys: |
             ${{ runner.os }}-gradle-
-            
-      - name: Pre-download Gradle and Build (Parallel with Emulator)
-        run: |
-          echo "Pre-downloading Gradle and building while emulator boots..."
-          # Download Gradle wrapper in background
-          ./gradlew --version &
-          # Start building APKs in background  
-          ./gradlew :integration-tests:assembleDebug :integration-tests:assembleDebugAndroidTest --no-daemon &
-          echo "Build started in background..."
-            
+
+      # SDK-170 follow-up: the previous "Pre-download Gradle and Build (Parallel with
+      # Emulator)" step backgrounded `./gradlew :integration-tests:assembleDebug
+      # :integration-tests:assembleDebugAndroidTest --no-daemon &`. On macos-15-intel
+      # the background process was resource-starved during emulator boot and usually
+      # finished or stalled before the action's Gradle started, so the race window
+      # was tiny. After we migrated to ubuntu-latest + KVM (commit 7d4a80ba), both
+      # Gradle processes get real CPU and run in true parallel, racing on
+      # `integration-tests/build/intermediates/merged_res_blame_folder/` and failing
+      # `:integration-tests:mergeDebugAndroidTestResources` with
+      # "Failed to create MD5 hash for file ... values-az.json as it does not exist".
+      #
+      # The action's `script:` invokes `./gradlew :integration-tests:connectedDebugAndroidTest`
+      # which transitively assembles the APKs, so removing the pre-build loses nothing
+      # except the (broken) parallelism. Wall-clock impact: ~30-90s on cold Gradle cache.
       - name: Run UI Tests with Emulator (KVM / x86_64)
         uses: ReactiveCircus/android-emulator-runner@v2
         with: