## Summary
Android apps which target SDK 31+ require specifying the mutability of any PENDING_INTENT. This is not supported in the upstream android-smsmms library: https://github.com/klinker41/android-smsmms/pull/193
Until the above PR is merged, we need a solution. I have pulled the code into https://invent.kde.org/sredman/android-smsmms and published the package in the Maven repository in gitlab.
BUG: 464392
## Test Plan
### Before:
Attempting to send an SMS or MMS message using kdeconnect-sms results in no message being sent, and an error being logged:
> V/Sending message: Sending new SMS
> E/Sending message: Exception
> java.lang.IllegalArgumentException: org.kde.kdeconnect_tp: Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
> Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
> at android.app.PendingIntent.checkFlags(PendingIntent.java:382)
> at android.app.PendingIntent.getBroadcastAsUser(PendingIntent.java:673)
> at android.app.PendingIntent.getBroadcast(PendingIntent.java:660)
> at com.klinker.android.send_message.Transaction.sendSmsMessage(Transaction.java:267)
> at com.klinker.android.send_message.Transaction.sendNewMessage(Transaction.java:158)
> at com.klinker.android.send_message.Transaction.sendNewMessage(Transaction.java:172)
> at org.kde.kdeconnect.Plugins.SMSPlugin.SmsMmsUtils.sendMessage(SmsMmsUtils.java:188)
> at org.kde.kdeconnect.Plugins.SMSPlugin.SMSPlugin.onPacketReceived(SMSPlugin.java:414)
> at org.kde.kdeconnect.Device.onPacketReceived(Device.java:570)
> <snipped for brevity>
### After:
SMS and MMS sends normally.
Motivation: We can't publish to the Play Store with a targetSdkVersion < 31
The new targetSdk required two changes:
* Specifying when activities, services and receivers should be exported or
not to other apps. For the ones I wasn't sure of what we want, I made
them exported to not break something.
* Specifying when a PendingIntent should be mutable or immutable. I made
them all mutable for now.
Official gradle docs recommend using settings.gradle file (see https://docs.gradle.org/current/userguide/organizing_gradle_projects.html#always_define_a_settings_file).
Blank Android projects in Android Studio declare their name and repositories in settings.gradle. Therefore, it makes sense to create such file here and add that information in it.
An explicit project name allows us to know exactly to what `project.name` resolves, instead of relying on the project root directory name, which can be changed by the developer locally.
