Revert "Upgrade targetSDK, minSDK and support libraries"

This reverts commit 70fa1803a62eb00de2ae441a02cdfad5b847969c.

Enable launching the camera app on Android 9 by (temporarily) reverting
the commit for upgrading the targetSdkVersion.

Issue: FP2P-322
Change-Id: Ic381dabbfab7a72603af9e3f7593d5d70d1deac4
diff --git a/build.gradle b/build.gradle
index 6e822e6..4baa8e5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,17 +2,16 @@
 
 buildscript {
     repositories {
-        google()
         jcenter()
+        maven { url 'http://repo1.maven.org/maven2' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.1'
+        classpath 'com.android.tools.build:gradle:1.0.0'
     }
 }
 
 allprojects {
     repositories {
-        google()
         jcenter()
     }
 }
@@ -22,12 +21,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 23
+    buildToolsVersion "21.1.2"
 
     defaultConfig {
         applicationId "com.fairphone.programmablebutton"
-        minSdkVersion 28
-        targetSdkVersion 28
+        minSdkVersion 17
+        targetSdkVersion 23
     }
 
     buildTypes {
@@ -50,6 +50,7 @@
         }
 
         // Move the tests to tests/java, tests/res, etc...
+        instrumentTest.setRoot('tests')
         androidTest.setRoot('tests')
         
         // Move the build types to build-types/<type>
@@ -64,5 +65,5 @@
 }
 
 dependencies {
-    implementation 'androidx.appcompat:appcompat:1.1.0'
+    compile 'com.android.support:support-v4:23.4.0'
 }