Revert "Revert "Revert "Use Java 11 source code"""

This reverts commit 23afa02cad957e4426cc7fc872910c6f0b556cb5.

Change-Id: I0dc76749a7084473a5c15e84032f0ba5058cac72

Conflicts:
	attachment-viewer/build.gradle
	library/ui-styles/build.gradle
	matrix-sdk-android-rx/build.gradle
	matrix-sdk-android/build.gradle
	vector/build.gradle

attachment-viewer/build.gradle

@@ -37,7 +37,7 @@ android {
         targetCompatibility versions.targetCompat
     }
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = '1.8'
     }
 
     buildFeatures {

dependencies.gradle

@@ -3,8 +3,8 @@ ext.versions = [
         'minSdk'            : 21,
         'compileSdk'        : 30,
         'targetSdk'         : 30,
-        'sourceCompat'      : JavaVersion.VERSION_11,
-        'targetCompat'      : JavaVersion.VERSION_11,
+        'sourceCompat'      : JavaVersion.VERSION_1_8,
+        'targetCompat'      : JavaVersion.VERSION_1_8,
 ]
 
 def gradle = "7.0.2"

diff-match-patch/build.gradle

@@ -3,3 +3,6 @@ apply plugin: 'java-library'
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 }
+
+sourceCompatibility = "8"
+targetCompatibility = "8"

library/ui-styles/build.gradle

@@ -36,16 +36,13 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
-
     compileOptions {
         sourceCompatibility versions.sourceCompat
         targetCompatibility versions.targetCompat
     }
-
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = '1.8'
     }
-
     buildFeatures {
         viewBinding true
     }

matrix-sdk-android-rx/build.gradle

@@ -27,7 +27,7 @@ android {
     }
 
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = "1.8"
     }
 }
 

matrix-sdk-android/build.gradle

@@ -71,7 +71,7 @@ android {
     }
 
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = "1.8"
     }
 
     sourceSets {

vector/build.gradle

@@ -302,7 +302,7 @@ android {
     }
 
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = "1.8"
     }
 
     sourceSets {