Set up SDK & reusable map view component (#476)

Adds `libraries/map` which contains some initial building blocks that will be used by the location sharing feature.

Ref: https://github.com/vector-im/element-meta/issues/1684

features/location/impl/src/main/AndroidManifest.xml

@@ -0,0 +1,21 @@
+<!--
+  ~ Copyright (c) 2023 New Vector Ltd
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
+</manifest>

features/location/impl/src/main/kotlin/io/element/android/features/location/impl/LocationUpdatesFlowImpl.kt

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.location.impl
+
+import android.Manifest
+import android.content.Context
+import android.location.LocationManager
+import androidx.annotation.RequiresPermission
+import androidx.core.content.getSystemService
+import androidx.core.location.LocationListenerCompat
+import androidx.core.location.LocationManagerCompat
+import androidx.core.location.LocationRequestCompat
+import io.element.android.libraries.core.coroutine.CoroutineDispatchers
+import io.element.android.features.location.api.Location
+import kotlinx.coroutines.asExecutor
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.channels.trySendBlocking
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+
+/**
+ * Returns a cold [Flow] that, once collected, emits [Location] updates every second.
+ */
+@RequiresPermission(
+    anyOf = [
+        Manifest.permission.ACCESS_COARSE_LOCATION,
+        Manifest.permission.ACCESS_FINE_LOCATION
+    ]
+)
+fun locationUpdatesFlow(
+    context: Context,
+    coroutineDispatchers: CoroutineDispatchers,
+): Flow<Location> = callbackFlow {
+    val locationManager: LocationManager = checkNotNull(context.getSystemService())
+    val provider = locationManager.bestAvailableProvider()
+    // Try to eagerly emit the last known location as fast as possible
+    locationManager.getLastKnownLocation(provider)?.let { location ->
+        trySendBlocking(
+            Location(
+                lat = location.latitude,
+                lon = location.longitude,
+                accuracy = location.accuracy
+            )
+        )
+    }
+    val locationListener = LocationListenerCompat { location ->
+        trySendBlocking(
+            Location(
+                lat = location.latitude,
+                lon = location.longitude,
+                accuracy = location.accuracy
+            )
+        )
+    }
+    LocationManagerCompat.requestLocationUpdates(
+        locationManager,
+        provider,
+        buildLocationRequest(),
+        coroutineDispatchers.io.asExecutor(),
+        locationListener,
+    )
+    awaitClose {
+        LocationManagerCompat.removeUpdates(locationManager, locationListener)
+    }
+}
+
+private fun LocationManager.bestAvailableProvider(): String =
+    checkNotNull(getProviders(true).maxByOrNull { providerPriority(it) }) {
+        "No location provider available"
+    }
+
+private fun providerPriority(provider: String): Int = when (provider) {
+    LocationManager.FUSED_PROVIDER -> 4
+    LocationManager.GPS_PROVIDER -> 3
+    LocationManager.NETWORK_PROVIDER -> 2
+    LocationManager.PASSIVE_PROVIDER -> 1
+    else -> 0
+}
+
+private fun buildLocationRequest() = LocationRequestCompat.Builder(1_000).apply {
+    setMinUpdateIntervalMillis(1_000)
+}.build()