android: Install the libmpd.so output on android

libmpd.so was getting written as a file called `arm64-v8a` instead of `arm64-v8a/libmpd.so`

android/apk/meson.build

@@ -1,13 +0,0 @@
-android_abi = get_option('android_abi')
-
-mpd_so = custom_target(
-  'libmpd.so',
-  output: 'libmpd.so',
-  input: mpd,
-  command: [
-    'cp',
-    '@INPUT@',
-    join_paths(meson.current_source_dir(), '../app/src/main/jnilibs/', android_abi),
-  ],
-  build_by_default: true
-)

android/build.py

@@ -68,3 +68,5 @@ run_meson(toolchain, mpd_path, '.', configure_args)
 
 ninja = shutil.which("ninja")
 subprocess.check_call([ninja], env=toolchain.env)
+
+subprocess.check_call([ninja, 'install'], env=toolchain.env)

meson.build

@@ -597,9 +597,13 @@ if is_android
     declare_dependency(sources: [bridge_header]),
     java_dep,
   ]
+
+  android_abi = get_option('android_abi')
+  install_dir = meson.current_source_dir() / 'android/app/src/main/jnilibs' / android_abi
 else
   target_type = 'executable'
   target_name = 'mpd'
+  install_dir = ''
 endif
 
 mpd = build_target(
@@ -637,19 +641,17 @@ mpd = build_target(
   ],
   link_args: link_args,
   build_by_default: not get_option('fuzzer'),
-  install: not is_android
+  install : true,
+  install_dir: install_dir
 )
 
-if is_android
-  subdir('android/apk')
-endif
-
 configure_file(output: 'config.h', configuration: conf)
 
 if systemd_dep.found()
   subdir('systemd')
 endif
 
+if not is_android
   install_data(
     'mpd.svg',
     install_dir: join_paths(get_option('datadir'), 'icons', 'hicolor', 'scalable', 'apps'),
@@ -659,6 +661,7 @@ install_data(
     'AUTHORS', 'COPYING', 'NEWS', 'README.md',
     install_dir: join_paths(get_option('datadir'), 'doc', meson.project_name()),
   )
+endif
 
 subdir('doc')