Add compile encoding option to prevent possible strange xml malformation

twidere.component.common/build.gradle

@@ -67,6 +67,7 @@ android {
     }
 
     compileOptions {
+        encoding = 'UTF-8'
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }

twidere.component.nyan/build.gradle

@@ -31,6 +31,7 @@ android {
     }
 
     compileOptions {
+        encoding = 'UTF-8'
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }

twidere/build.gradle

@@ -111,6 +111,7 @@ android {
     }
 
     compileOptions {
+        encoding = 'UTF-8'
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }