ci: Specify to build winit package when invoking cargo-apk (#2561)

* ci: Don't use `$CMD` for Android doc building

Since migrating `cargo-apk` to `clap` [it is now annoying] to pass
unknown arguments to an underlying `cargo` command (like `cargo doc`):
fortunately generating docs doesn't need to go through `cargo apk` to
set up cross-compiler/linker environment variables at all.

[it is now annoying]: rust-mobile/ndk#363

* ci: Simplify

* ci: Explicitly build just the `winit` package on Android

Since rust-mobile/cargo-subcommand#23 `cargo-apk`
now strictly searches for workspaces first before committing to finding
the right package _within said workspace_, and bails when no package was
selected since we don't support selecting (building, packaging, running)
>1 target currently.

Perhaps it's a bit hash to enforce this on free-form `cargo apk --`
invocations, but it is what it is.

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
           - { target: x86_64-unknown-linux-gnu, os: ubuntu-latest,   }
           - { target: x86_64-unknown-linux-gnu, os: ubuntu-latest, options: --no-default-features, features: x11 }
           - { target: x86_64-unknown-linux-gnu, os: ubuntu-latest, options: --no-default-features, features: "wayland,wayland-dlopen" }
-          - { target: aarch64-linux-android,    os: ubuntu-latest,  cmd: 'apk --', features: "android-native-activity" }
+          - { target: aarch64-linux-android,    os: ubuntu-latest, options: -p winit, cmd: 'apk --', features: "android-native-activity" }
           - { target: x86_64-apple-darwin,      os: macos-latest,    }
           - { target: x86_64-apple-ios,         os: macos-latest,    }
           - { target: aarch64-apple-ios,        os: macos-latest,    }
@@ -75,7 +75,7 @@ jobs:
 
     - name: Check documentation
       shell: bash
-      run: cargo $CMD doc --no-deps --target ${{ matrix.platform.target }} $OPTIONS --features $FEATURES --document-private-items
+      run: cargo doc --no-deps --target ${{ matrix.platform.target }} $OPTIONS --features $FEATURES --document-private-items
 
     - name: Build crate
       shell: bash
@@ -88,11 +88,11 @@ jobs:
 
     - name: Run tests
       shell: bash
-      if: (
+      if: >
         !contains(matrix.platform.target, 'android') &&
         !contains(matrix.platform.target, 'ios') &&
         !contains(matrix.platform.target, 'wasm32') &&
-        matrix.rust_version != '1.60.0')
+        matrix.rust_version != '1.60.0'
       run: cargo $CMD test --verbose --target ${{ matrix.platform.target }} $OPTIONS --features $FEATURES
 
     - name: Lint with clippy
@@ -106,9 +106,9 @@ jobs:
       run: cargo $CMD test --no-run --verbose --target ${{ matrix.platform.target }} $OPTIONS --features serde,$FEATURES
     - name: Run tests with serde enabled
       shell: bash
-      if: (
+      if: >
         !contains(matrix.platform.target, 'android') &&
         !contains(matrix.platform.target, 'ios') &&
         !contains(matrix.platform.target, 'wasm32') &&
-        matrix.rust_version != '1.60.0')
+        matrix.rust_version != '1.60.0'
       run: cargo $CMD test --verbose --target ${{ matrix.platform.target }} $OPTIONS --features serde,$FEATURES