Update default Android API level to at least 23

[nanangizz]

Some commonly used third-party libraries (e.g: OpenSSL, OpenH264) require a minimum API level of 23, while the default API level may be too low (e.g: for NDK r27c, it is 21).

For example, when using NDK r27c, the configure script fails to detect OpenSSL and OpenH264. The config.log shows errors such as:

ld.lld: error: undefined symbol: stdin
ld.lld: error: undefined symbol: stderr

[Copilot]

Pull Request Overview

This PR updates the configure-android script to enforce a minimum Android API level of 23, which is required by commonly used third-party libraries like OpenSSL and OpenH264. When using recent NDK versions (e.g., r27c), the default minimum platform level might be 21, which causes detection failures for these libraries.

• Adds minimum API level enforcement to bump any detected API level below 23 up to 23
• Updates help documentation to reflect this new minimum requirement

Comments suppressed due to low confidence (1)

configure-android:66

• The minimum API level enforcement (lines 58-60) only applies when APP_PLATFORM is auto-detected. If a user explicitly sets APP_PLATFORM to a value less than 23 (e.g., APP_PLATFORM=android-21), the enforcement is bypassed, leading to the same OpenSSL/OpenH264 detection failures the PR aims to fix. The enforcement should be moved outside the if test \"x$APP_PLATFORM\" = \"x\" block to apply universally, after extracting the numeric value from user-provided values like "android-21".

if test "x$APP_PLATFORM" = "x"; then
  if test -d ${ANDROID_NDK_ROOT}/platforms; then
    APP_PLATFORM=`ls ${ANDROID_NDK_ROOT}/platforms/ | sed 's/android-//' | sort -gr | head -1`
  elif test -f ${ANDROID_NDK_ROOT}/meta/platforms.json; then
    if ! [ -x "$(command -v jq)" ]; then
      APP_PLATFORM=`cat ${ANDROID_NDK_ROOT}/meta/platforms.json  | grep -o '"min":[[:space:]]*[[:digit:]]*' | head -1 | grep -o '[[:digit:]]*' `
    else
      APP_PLATFORM=`cat ${ANDROID_NDK_ROOT}/meta/platforms.json  | jq -r ".min"`
    fi
  fi
  if test "x$APP_PLATFORM" != "x"; then
    if [ "$APP_PLATFORM" -lt "23" ]; then
      APP_PLATFORM="23"
    fi
    APP_PLATFORM="android-${APP_PLATFORM}"
  else
    APP_PLATFORM="latest"
  fi
  echo "$F: APP_PLATFORM not specified, using ${APP_PLATFORM}"
fi