feat: add a tablet friendly mode (#782)

app/src/main/AndroidManifest.xml

@@ -135,7 +135,7 @@
         <activity
             android:name="com.geeksville.mesh.MainActivity"
             android:launchMode="singleInstance"
-            android:screenOrientation="sensorPortrait"
+            android:screenOrientation="unspecified"
             android:windowSoftInputMode="stateAlwaysHidden"
             android:theme="@style/Theme.App.Starting"
             android:exported="true">

app/src/main/java/com/geeksville/mesh/ui/ChannelFragment.kt

@@ -333,7 +333,7 @@ fun ChannelScreen(
                 painter = channelSet.qrCode?.let { BitmapPainter(it.asImageBitmap()) }
                     ?: painterResource(id = R.drawable.qrcode),
                 contentDescription = stringResource(R.string.qr_code),
-                contentScale = ContentScale.FillWidth,
+                contentScale = ContentScale.Inside,
                 alpha = if (enabled) 1f else 0.25f,
                 // colorFilter = ColorFilter.colorMatrix(ColorMatrix().apply { setToSaturation(0f) }),
                 modifier = Modifier