Rolled-back our change to min/target SDK version, now 22. Fixes HostID =...

Rolled-back our change to min/target SDK version, now 22. Fixes HostID = unknown and crash on internal sampling.

app/build.gradle

@@ -32,12 +32,12 @@ def computeVersionCode = { ->
     return VersionCode
 }
 android {
-    compileSdkVersion 28
+    compileSdkVersion 22
     buildToolsVersion '28.0.3'
     defaultConfig {
         applicationId "fieldscience.cs.earlham.edu.fieldday"
         minSdkVersion 21
-        targetSdkVersion 28
+        targetSdkVersion 22
         versionName "fieldDay_" + getGitHash() + "_" + getVersionCode() + ".apk"
     }
     buildTypes {

app/src/main/java/fieldscience/cs/earlham/edu/fieldday/DatabaseActionsActivity.java

@@ -11,6 +11,7 @@ import android.content.SharedPreferences;
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.text.Editable;
@@ -44,7 +45,7 @@ public class DatabaseActionsActivity extends Activity {
     EditText dbName, username, password, server, port;
     Button setup, upload, clean;
     private String uname, database, pass, host, pNum;
-    static final String hostid = android.os.Build.SERIAL;
+    static final String hostid = Build.SERIAL;
 
     public static String trip, url;
     public static int tripID, downloadColumnCount = 0, uploadColumnCount = 0;

app/src/main/java/fieldscience/cs/earlham/edu/fieldday/ReadingsDatabase.java

@@ -7,6 +7,7 @@ import android.database.sqlite.SQLiteConstraintException;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteException;
 import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Build;
 import android.os.Environment;
 import android.util.Log;
 import android.util.Pair;
@@ -76,7 +77,7 @@ public class ReadingsDatabase extends SQLiteOpenHelper {
 
     public Context context;
 
-    static final String host = android.os.Build.SERIAL;
+    static final String host = Build.SERIAL;
     private static final int DATABASE_VERSION = 1;
     public static File dbPath;
     public static String[] tables = {T_HOST, T_TRIP, T_SITE, T_SECTOR, T_SPOT, T_PLATFORM, T_SENSOR};