android: require SDK version 14

Closes #213.

NEWS

@@ -2,6 +2,8 @@ ver 0.20.17 (not yet released)
 * output
   - alsa: fix crash bug with 8 channels
 * fix real-time and idle scheduling with Musl
+* Android
+  - fix compatibility with Android 4.0
 
 ver 0.20.16 (2018/02/03)
 * output

android/AndroidManifest.xml

@@ -5,7 +5,7 @@
           android:versionCode="16"
           android:versionName="0.20.17">
 
-  <uses-sdk android:minSdkVersion="9" android:targetSdkVersion="17"/>
+  <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="17"/>
 
   <application android:icon="@drawable/icon" android:label="@string/app_name">
     <activity android:name=".Main"

android/build.py

@@ -46,7 +46,7 @@ class AndroidNdkToolchain:
 
         self.ndk_arch = 'arm'
         android_abi = 'armeabi-v7a'
-        ndk_platform = 'android-21'
+        ndk_platform = 'android-14'
 
         # select the NDK compiler
         gcc_version = '4.9'
@@ -87,7 +87,7 @@ class AndroidNdkToolchain:
         self.cppflags = '--sysroot=' + sysroot + \
             ' -isystem ' + os.path.join(install_prefix, 'include') + \
             ' -isystem ' + os.path.join(sysroot, 'usr', 'include', arch) + \
-            ' -D__ANDROID_API__=21'
+            ' -D__ANDROID_API__=14'
         self.ldflags = '--sysroot=' + sysroot + \
             ' -L' + os.path.join(install_prefix, 'lib') + \
             ' -L' + os.path.join(target_root, 'usr', 'lib') + \