Remove 'Setup NDK' step from CI workflow

It appears that this setup is no longer required for any of the
workflow jobs.

Author: bigdaz

.github/workflows/ci-check.yml

@@ -40,17 +40,6 @@ jobs:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     -   uses: actions/checkout@v1
 
-    # Sets up the NDK required by AGP 3.6.x
-    -   name: NDK Cache
-        id: ndk-cache
-        uses: actions/cache@v2
-        with:
-          path: /usr/local/lib/android/sdk/ndk/20.0.5594570
-          key: ndk-cache-20.0.5594570
-    -   name: Setup NDK
-        if: steps.ndk-cache.outputs.cache-hit != 'true'
-        run: sudo $ANDROID_HOME/tools/bin/sdkmanager 'ndk;20.0.5594570'
-
     # Use Java 8
     -   uses: actions/setup-java@v1
         with:
@@ -77,17 +66,6 @@ jobs:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     -   uses: actions/checkout@v1
 
-    # Sets up the NDK required by AGP 3.6.x
-    -   name: NDK Cache
-        id: ndk-cache
-        uses: actions/cache@v2
-        with:
-          path: /usr/local/lib/android/sdk/ndk/20.0.5594570
-          key: ndk-cache-20.0.5594570
-    -   name: Setup NDK
-        if: steps.ndk-cache.outputs.cache-hit != 'true'
-        run: sudo $ANDROID_HOME/tools/bin/sdkmanager 'ndk;20.0.5594570'
-
     # Patch issue in platform-tools 31.0.3 where platform-tools/api/api-versions.xml is missing (see https://issuetracker.google.com/issues/195445762)
     -   name: Patch api-versions
         run: sudo test -f $ANDROID_HOME/platform-tools/api/api-versions.xml || (sudo mkdir $ANDROID_HOME/platform-tools/api && sudo cp .github/api-versions.xml $ANDROID_HOME/platform-tools/api/api-versions.xml)